New Gateway to Computer Science 10

Let’s Review

 Electronic Transaction Act deals with the issues that are related to cybercrime.
 The electronic transaction and digital signature is valid not only for the private
sector but also for the government agencies.
 Digital citizenship refers to the responsible use of technology by anyone who uses
computers, the internet, and digital devices to engage with society on any level.
 A digital footprint is a track of data that you create while using the internet.
 Human life is being easier due to the use of social media.
 Social media are the integral part of the marketing strategy of many business
organizations.
 Facebook is a one of the world’s largest social network platform.
 Wikipedia was founded in 2001 January.

Innovative Task

Ask with any 20 people in locality and prepare a report about what types of social
media that they are using? How long time they use it in a day? And what type of
information and content they like to read?

Assignment

1. Select the best answer from the given options.

a. The first IT policy was introduced in Nepal in:

i. 2057 BS ii. 2061 BS iii. 2052 BS iv. 2072 BS

b. Which of the following is social media?

i. Photoshop ii. Facebook iii. Graphics iv. Television

c. When Electronic Transaction Act was approved in Nepal?

i. 2054 BS ii. 2063 BS iii. 2073 BS iv. 2050 BS

d. Which of the following is related to digital citizenship?

i. Communicating with respect ii. Harming to others with technology

iii. Junk Mails iv. Doing piracy

e. Which of the following is active digital footprint?

i. Posting on facebook ii. Filling online forms

iii. Chatting with others iv. Both i and ii

50 New Gateway to Computer Science Book -10

2. Write down the full form for the followings.

ICT IPVT VoIP MDGs E-Commerce

3. State whether the following statements are true or false.

a. ICT stands for Information Computer Technology.

b. As the goal of ICT 99% of all citizen facing government services would be offered
on line by 2020 .

c. To create conditions for the intensified development and growth of ICT sector as
a key driver for Nepal’s sustainable development and poverty reduction strategies
is the mission of ICT policy of Nepal.

d. To promote ICT to further productivity among the sectors that is key drivers of the
national economy is the strategies of ICT policy of Nepal

e. The overall goals of Information and Communication Technology Policy will be
achieved through the mobilization of both public and private sector resources.

f. Electronic Transaction Act deals with the issues that are related to computer
software.

g. Social media allows you to connect directly with your audience.

4. Fill in the blanks with correct words / phrases.

a. ………………. issues arising from the use of technology in all areas of our lives,
business, health sector, education sector and so on.

b. The goal of ICT is at least ……………. present of the population will have digital
literacy skills by the end of 2020.

c. To transform Nepal into an information and knowledge-based society and
economy is the ……………. of ICT policy of Nepal.

d. Hon. Minister, Ministry of Information and Communication Technology will be
the…………… of National Information and Communication Technology Policy
Implementation Steering Committee.

e. A …………….. is a track of data that you create while using the internet.

f. Publishing a …………… and posting s………………. updates are another
popular ways to expand your digital footprint.

g. ……………… is a platform for casual dialogue and discussions on a specific
topic or opinion.

New Gateway to Computer Science Book -10 51

5. Answer the following questions.
a. When first ICT policy of Nepal was introduced?
b. Why ICT policy is needed in Nepal?
c. Write any three guiding principles of the ICT policy.
d. Write down the vision and mission of government related to ICT policy.
e. Write any ten policies of ICT policy.
f. List the working structure committee of A National Information and
Communication Technology Policy.
g. Write any five objectives of ICT policy.
h. What is electronic transaction act? When it was approved in Nepal?
i. What is digital citizenship? Write with examples.
j. Define digital footprint? What are the active and passive digital footprints? Write
with examples.
k. What do you mean by social media? What are the various social media and
popularly used in our country?
l. Mention any five opportunities and threats of using social media.
m. Name any five platforms of social media.

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Lesson

3 Computer Security System

Learning Outcomes

At the end of this lesson, students will be able to:
 define computer security.
 tell about security threats and malicious code.
 explain the various security mechanism.
 tell about computer antivirus programs.
 tell about backup system .
 explain about various hardware security measures.

Computer security is also known as cyber security
or IT security. It is the way of protecting information
systems, computer hardware and software from theft
or damage. Computer security includes controlling
physical access to the hardware, as well as protecting
against harm that may come through network access,
data and code. Cyberspace is becoming a dangerous
place for all organizations and individuals to protect
their sensitive data. This is because of the many people and machines accessing it. The
protection given to the different types of hardware and software tools of the computer
system is known as computer security.

Prevention of data theft such as password, ATM pin, Credit card information, bank account
numbers, documents, etc. is essential since many of our day to day activities depend on
the security. The data stored in a computer can also be misused by an unauthorized user.
Anyone can modify and change the program source codes and can also use our pictures or
email accounts to do fake activities on you. Therefore, it is necessary to protect hardware
components and software programs of your computer system. Computer Security has
four main areas which are listed below.

The key principles of information security are listed below.

 Confidentiality: It means only authorized users can access the data resources and
information.

New Gateway to Computer Science Book -10 53

 Integrity: It means only authorized users should be able to modify and edit the data
when needed.
 Availability: It means data should be available to users when user is needed.
 Authentication: It means you are communicating with the one to whom you think to
communicate or not.

Let’s Review

 Computer security is also known as cyber security or IT security.
 Computer security is the way of protecting of information systems from theft or
damage.
 The data stored in a computer can also be misused by an unauthorized user.
 Confidentiality means only authorized users can access the data resources and
information.
 Integrity means only authorized users should be able to modify and edit the data
when needed.

Security Threats

We all have to be secure in our office, locality, home, city, country and in this global
world. These days, protecting the computer system from the threats is very challenging. A
threat refers to anything that has the potential to cause serious harm to a computer system.
A threat can be malicious program, a natural disaster or a thief. Security threats may occur
from the user computer hardware and computer software. The aims of some types of
threats are; to get information from the system (without affecting the system resources)
and to alter the system resources or affect its operations.

Malicious Codes

Malicious code is the term used to describe any code in any part of a software system or
script that is intended to cause undesired effects, security breaches or damage to a system.
Malicious code is an application security threat that cannot be efficiently controlled by
conventional antivirus software. Malicious code describes a broad category of system
security terms that includes attack scripts, viruses, worms, Trojan horses, backdoors and
malicious active content.
Malicious code can enter network drives and spread on another system as well. Malicious
code can also cause network and mail server overload by sending email messages;
stealing data and passwords; deleting document files, email files or passwords; and even
reformatting hard drives.

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Security Mechanism

Security mechanisms deal with prevention, detection, and recovery from a security attack.
Prevention involves mechanisms to prevent the computer from being damaged. Detection
requires mechanisms that allow detection of when, how, and by whom an attacked
occurred. Recovery involves mechanisms to stop the attack, assess the damage done, and
then repair the damage. Security mechanisms are built using personal and technology.
Personal are used to frame security policy and procedures, and for training and awareness.
Security mechanisms use technologies like cryptography, digital signature, firewall,
user identification and authentication, and other measures like intrusion detection, virus
protection, data and information backup as countermeasures for security attack. Let’s
discuss some of the security mechanism below.

Authentication System

Authentication is the process of ensuring and confirming the identity of the user before
revealing any information to the user. It provides confidence in the identity of the user or
the entity connected. It also assures that the source of the received data is claimed.
Authentication is facilitated by the use of username and password, smart card, biometric
methods like retina scanning and fingerprints.

Password: Passwords are the most common tool for restricting
access to the computer system. It is a set of secret characters or
words used to authenticate access to a digital system. Passwords
help ensure that computers or data can only be accessed by
those who have been granted the right to view or access them.
Passwords are typically used with a username. It can vary in length and can contain
letters, numbers and some other special characters. There are many authentication options
available today so that users do not have to depend on passwords that can be easily
cracked or compromised.

Biometric: Biometric technology is mainly used for
identification and access control. Biometrics includes
physiological characteristics such as fingerprints or retinal
scans, and behavioural characteristics such as typing patterns
and voice recognition system. A biometric system is a
technological system that uses information about a person to
identify that person. Biometric systems depend on specific
data about unique biological behaviours in order to work effectively. Any government
organizations, businesses and other organizations can use biometric systems to get more
information about the individuals. Many biometric systems are developed for security

New Gateway to Computer Science Book -10 55

applications. An airport scanning device, a “bio-password” system, or an internal data
gathering protocol is an example of a biometric system that uses identifying data for a
security result.

Firewalls

A firewall is a security mechanism to protect a local network from the threats it may face
while interacting with other networks (Internet). You can implement a firewall in either
hardware or software form, or a combination of both. Firewalls prevent unauthorized
internet users from accessing private networks connected to the internet, especially
intranets. A firewall is the most basic and oldest form of network security. The primary
function of firewall is to monitor network traffic and to prevent unauthorized access
between computer networks. Some of the basic functions of firewall are given below.

 It provides security by examining the incoming data packets and allowing them to
enter the local network only if the conditions are met.

 It provide user authentication by verifying the username and password.

 It can be used for holding the structure and contents of a local network from external
users.

Cryptography

Cryptography is the science of writing information in a ‘hidden’ or ‘secret’ form and is an
ancient art. It is necessary when communicating data over any network, particularly the
Internet. It protects the data in transit and also the data stored on the disk. Cryptography
is technique of securing information and communications through use of codes so that
only those people for whom the information is intended can understand it and process
it. In Cryptography the techniques which are used to protect information are obtained
from mathematical concepts and a set of rule based calculations known as algorithms to
convert messages in ways that make it hard to decode it. Cryptography is often associated
with the process where an ordinary plain text is converted to cipher text which is the text
made such that intended receiver of the text can only decode it and hence this process is
known as encryption. The process of conversion of cipher text to plain text this is known
as decryption.

Encryption: Encryption is the process of converting plaintext to cipher text, using an
encryption algorithm. Encryption takes readable data and alters it so that it appears
random. Encryption requires the use of an encryption key which is a set of mathematical
values. Encryption is commonly used to protect data in transit and data at rest. Every time
someone uses an ATM or buys something online with a smartphone, encryption is used to
protect the information being relayed. Businesses are increasingly relying on encryption

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to protect applications and sensitive information from Plaintext

reputational damage when there is a data crack. The primary Encryption Decryption
Benefits of encryption is to protect the confidentiality of
digital data stored on computer systems or transmitted
over the internet or any other computer network.

Decryption: It is the reverse of encryption, i.e. converting

cipher text to plaintext, using decryption algorithm. Ciphertext
Decryption is the process of decoding encrypted

information so that is can be accessed again by authorized users. In decryption, the

system extracts and converts the garbled data and transforms it to texts and images that

are easily understandable not only by the reader but also by the system. Decryption may

be accomplished manually or automatically. It may also be performed with a set of keys

or passwords.

Antivirus Software

Antivirus software is a type of utility software. It is used
for scanning and removing viruses and malware from
your computer. The main use of antivirus program is to
protect computers from viruses and remove the viruses
that are detected. Most of the antivirus programs have both
automatic and manual scanning capacity. The automatic
scan check files are downloaded from the Internet, saved
using disk that are inserted into the computer, and files.
The automatic scan scans the entire hard drive on a regular
basis. The manual scan option allows you to scan individual files or your entire system
whenever required.

Backup System

The process of making duplicate copies of data or
programs so that these additional copies can be used to
restore the original one after data loss. These additional
copies of data and programs are typically called
“backups”. You can back up content, data, and settings
even from your android device with the help of Google
account. You can restore your backed-up information to
the concerned device connected or to another device. To
secure our data or information we can backup them like
in pen drive, memory card, external hard disk, Google drive, or even in cloud storage.

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Let’s Review

 A threat refers to anything that has the potential to cause serious harm to a computer
system.
 Security threats may occur from the user computer hardware and computer
software.
 Malicious code can enter network drives and spread on another system as well.
 Security mechanisms deal with prevention, detection, and recovery from a security
attack.
 Security mechanisms use technologies like cryptography, digital signature, firewall,
user identification and authentication, and other measures.
 Authentication is the process of ensuring and confirming the identity of the user
before revealing any information to the user.
 A biometric system is a technological system that uses information about a person
to identify that person.
 Firewalls prevent unauthorized internet users from accessing private networks
connected to the internet, especially intranets.
 Cryptography is technique of securing information and communications through
use of codes so that only those people for whom the information is intended can
understand it and process it.
 Encryption is the process of converting plaintext to cipher text.
 Decryption is the process of decoding encrypted information so that is can be
accessed again by authorized users.

Hardware Security

The protraction or security given to different computer parts and other peripheral devices
is called hardware security. If any physical part of the computer stops to work, the entire
system may not respond. Dust, heat, low or high temperature, voltage fluctuations, etc.
may cause serious problem on the hardware components. We can apply the given security
mechanisms to protect the hardware components of the computer system.

Regular Maintenance

Regular maintenance of a computer means taking regular steps that make your computer
work faster and more secure. Computer may get slow down and be unable to perform the
task, at that moment we can do proper maintenance and fix the errors that occur. Regular
maintenance helps us to find the hardware problems and keep the individual parts of
computer in good condition.

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Free from Dust

The dust particles from the external environment is the major cause of the failure of
different computer components such as keyboard, mouse, RAM, CD/DVD drive, USB
port, Hard disk, Memory cards, etc. Other internal parts like motherboard, chips or
transistors also may stop to work because of dust. To remove such issues mentioned
above, we must protect hardware components from dust. We can keep the room neat and
clean, flooring of computer room with carpet and cover the computer system when they
are not in use.

Air Condition System

A computer room with proper air condition maintains the temperature, air distribution
and humidity. Computer system produces more heat, so the room must have proper
ventilation system. The dust and small fiber materials get placed around the processor and
jams it so that its heat does not get dissipated. As a result, processor trips on overheating.
Similarly, the fan in the power supply is unable to dissipate heat and many parts of the
computer get so much of dust and may not work in a proper way. The temperature in the
computer system should be maintained between 21oC to 50oC and humidity of 50% with
5% variation.

Fire Protection Devices

The short circuit in electric wires may cause fire in a room which
may damage the parts of the computer or the entire computer system.
It is a serious problem of an individual user and of an organization.
To prevent from this accident, we must have fire extinguishers in
order to control fire. We can use fire detecting technology or fire
warning alarms technology to minimize such accidents.

Insurance Policy

Computer insurance provides cover for loss or damage of computer equipment that
may be desktop computers, laptop and handheld computers, peripheral components,
or networked system, and other portable equipment. Insurance is available for the cost
of replacing software and re-inputting any lost data. The valuable data and information
stored on computer for further use cannot recover with the insurance policy but a user can
claim for the cost of hardware damage and loss of software programs.

Use of Power Protection Devices

A computer needs constant source of electrical power to work. When an unexpected
power failure occurs and the computer shuts down improperly, that may damage the
hard drive and other internal components. Having a low or high power supply can cause
problems as well. High voltage can overheat the system and low voltage can prevent the
computer from preforming at its optimal level. Power protection devices help to protect
the computer system from the voltage fluctuation. Some of the power protection devices
are explained below.

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Surge Suppressor

Surge suppressor helps to protect the device against the damage from
surges and spikes. These devices are used to filter the effects of voltage
spikes and surges that are present in power sources. A good surge
suppressor will protect your system from most of the voltage problems.

Uninterruptible Power Supply (UPS)

The UPS helps to protect against potential electrical power problems by
supplying a consistent level of electrical power to a computer or other
devices. The battery is constantly recharged while the UPS is in use. The
UPS provides a consistent power. Many UPS devices can communicate
directly with the computer operating system. This communication allows
the UPS to safely shut down the computer and save data during the power
failure. There are several types of UPS systems. Let’s discuss them in
short.

Standby UPS: It helps to protect against potential electrical power problems by providing
a backup battery to supply power when the incoming voltage drops below the normal
level.The battery is on standby during normal operation. When the voltage decreases, the
battery provides DC power to a power inverter, which converts it into AC power for the
computer.

Line Interactive UPS: This UPS has completely different design than the standby UPS.
This design replaces the separate battery charger, inverter, and source selection switch
with a combination inverter. When the line power is working, the inverter or converter
charges the battery; when the power fails, the system operates in reverse.

Double Conversion: It is an online UPS. It has no transfer time in the event of a power
failure.

Voltage Stabilizers

A voltage stabilizer stabilizes or regulates the voltage if the supply
voltage varies or fluctuates over a given range. It is an electrical
appliance that feeds constant voltage to a load during over and under
voltage conditions. This device detects these voltage conditions and
correspondingly brings the voltage to the desired range. Voltage
stabilizers provide a means to regulate the supply voltage to the load. These are not
meant to provide a constant voltage output; instead it operates the load or system in an
acceptable range of voltage. In case of modern digital type stabilizers, a microcontroller
or microprocessor is used as a central control unit.

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Spike Guard

A spike guard has multiple sockets for connecting
electrical and electronic devices. In addition, they also
provide protection against spikes which can occur from
time to time. The sudden voltage is known as spikes. It has
extra-long cable length. It can be used to connect multiple
pins of electronic devices. The outer housing is made up of a fire retardant material so it
is safe to use. The main use of spike guard is to remove the sudden voltage and prevent it
from entering into the main system.

Volt Guard

Volt guard is also called a power protection device. It controls
the fluctuation of electric voltage. The volt guard provides
constant output voltage to the computer system if high input
voltage is supplied from the source. It provides constant
output voltage between the ranges of 220 to 240 volts.

Let’s Review

 The security given to different computer parts and other peripheral devices are
called hardware security.
 Regular maintenance of a computer means taking regular steps that make your
computer faster and more secure.
 A computer room with proper air condition maintains the temperature and
humidity.
 To prevent the computer from fire we must have fire extinguishers.
 Computer insurance provides cover for loss or damage of computer equipment.
 Surge suppressor helps to protect the device against damage from the surges and
spikes.
 The UPS helps to protect against potential electrical power problems by supplying
a consistent level of electrical power to a computer or other devices.
 A voltage stabilizer regulates the voltage if the supply voltage fluctuates over a
given range.
 A spike guard has multiple sockets for connecting electrical and electronic devices.
 Volt guard controls the fluctuation of electric voltage.

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Innovative Task

 What are the various types of hardware and software security threats that may
occur in any organizations? How can we protect such threats? Prepare a project
report.

Assignment

1. Select the best answer from the list of choices.

a. Computer security is also called as ………..

i. cyber security ii. virus security ii. program security iv. File security

b. Which of the following is security threats?

i. Downloading software ii. Updating software

iii. Removing software iv. Computer Virus

c. Which of the following is authentication system?

i. Password ii. Biometric iii. Cryptography iv. All of the them

d. What do you mean by encryption?

i. Converting plain text to cipher text ii. Converting cipher text to plain text

iii. Both of them iv. None of them

e. Which of the following is related to back up?

i. Storing on secondary storage ii. storing on primary memory

iii. Storing on cloud storage iv. Both i and iii

f. The temperature in the computer system should be maintained between ....to ......

i. 21oC and 24oC iii. 22oC and 25oC

ii. 23oC and 26oC iv. None of the above

g. ....... protects the machine and peripheral hardware s from left, electronic intrusion

and damage.

i. Information security iii. Hardware security

ii. Software security iv. None of the above

h. To prevent the loss of data during power failures, use a(n):

i. encryption program. iii. surge protector.

ii. firewall. iv. UPS.

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i. A(n)…………… can shield electronic equipment from power spikes.

i. encryption program iii. surge protector

ii. firewall iv. UPS

j. A device that protects your PC against power surges and spikes.

i. UPS iii. Voltage regulator

ii. Surge suppressor iv. All of the above

2. Fill in the blanks with correct words / phrases.

a. ……………is also known as cyber security or IT security.

b. The data stored in a computer can also be misused by an ……………..user.

c. …………means only authorized users should be able to modify and edit the data
when it is needed.

d. ………..may occur from the user computer hardware and computer software.

e. ……………..code can enter network drives and spread on another system as well.

f. A ………………. system is a technological system that uses information about a
person to identify that person.

g. ……………………… is the way of protecting information systems from theft
or damage.

h. ………………… means only authorized users should be able to modify and edit
the data when needed.

i. The protection or security given to different computer parts and other
peripheral devices is called ……………….. security.

j. A computer room with proper …………………. maintains the temperature, air
distribution and humidity.

3. State whether the following statements are true or false.

a. Confidentiality means only authorized user can access the data resources and
information.

b. Computer security is the way of protecting of information system.

c. A threat refers to anything that has the potential to cause serious harm to a computer
system.

d. Security mechanisms deal with prevention, detection, and recovery from a security
attack.

e. Antivirus programs are like a virus which may cause serious problem in the
computer system.

New Gateway to Computer Science Book -10 63

f. Backup is the process of making duplicate copy of information stored on computer.
g. Regular maintenance of a computer means taking regular steps that make your
computer faster and more secure.
h. To prevent the computer from fire we must have backup storage.
i. Surge suppressor helps to protect the device against damage from the surges and
spikes.
j. A voltage stabilizer stabilizes or regulates the voltage if the supply voltage varies
or fluctuates over a given range.
k. Hard disk controls the fluctuation of electric voltage.
l. Hardware security is a means of ensuring that data are kept safe from corrupt
and loss.
4. Give an appropriate technical term for the following.
a. An application security threat that cannot be efficiently controlled by conventional
antivirus software.
b. It deal with prevention, detection, and recovery from a security attack.
c. It is the process of ensuring and confirming the identity of the user before revealing
any information to the user.
d. The most common tool for restricting access to the computer system.
e. A technological system that uses information about a person to identify that
person.
f. It is the process of converting plaintext to cipher text.
g. It is the process of decoding encrypted information so that is can be accessed
again by authorized users.
h. A battery supported power unit which supplies power during the failure of
electricity.
i. Device used to protect electronic device from high voltage.
j. A branch of technology that protects the machine from theft, corruption, or natural
disaster.
k. A device which provides continuous power to the computer equipment and protects
them from power surges and voltage fluctuations.
l. A device that protects your PC against power surges and spikes.

64 New Gateway to Computer Science Book -10

5. Match the following

Backup power protection device

Antivirus secret word or phrase

Password cloud storage

UPS remove computer viruses

Search engine

6. Answer the following questions.

a. What is the computer security? Write down the key principles of information
security.

b. What is security threats? How it occur?

c. Define malicious code with its examples.

d. What do you mean by security mechanism? Write some security mechanism.

e. Define authentication system.

f. Define the terms biometric and password.

g. What is firewall? Write its basic functions.

h. What is cryptography? Define encryption and decryption.

i. What is anti-virus software? Write with few examples.

j. What is backup? Why it is important in data security?

k. What is the hardware security? What are the means of hardware security?

l. Define UPS. What are the functions of UPS?

m. What is a voltage regulator?

n. What is a voltage fluctuation? Which device do you recommend to protect your

PC from voltage fluctuation?

o. What is the role of the UPS in computer security?



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Lesson

4 E-Commerce

Learning Outcomes

At the end of this lesson, students will be able to:
 define explain about e-commerce.
 tell the benefits and limitations of e-commerce.
 explain the types of e-commerce.
 tell about mobile commerce.
 tell about the online payment mechanism.

E-commerce is also known as electronic commerce or internet commerce. E-commerce
can be broadly classified as the set of business activities involving consumers, service
providers and manufacturers who use computer networks such as the Internet for
conducting their business transactions. It refers to any form of business transactions that
are conducted online. Ecommerce enables you to buy and sell products on a global scale,
twenty-four hours and 365 days. The most popular example of E-Commerce is online
shopping, which is defined as buying and selling of goods through the internet on any
device. However, E-Commerce can also involve other types of activities, such as online
sales, payment doorways, online ticketing, internet banking, etc.

It has become so convenient and easy, that anyone can shop for anything right from a living
room, with just a few clicks. This has evolved more with the emergence of smartphones,
where now, you can shop from anywhere and anytime, with a wireless device connected
to the Internet. Now you can search for almost any product or service online, without
having to go anywhere physically.

The primary goal of e-commerce is to bring the organizations closer to their actual
customers, thus providing the customers the products and services much faster and at
leaser cost than possible by the traditional business models. The other goals include
reduction in product and service cost, improve customer response time, improve the
quality of the products and services and improve customer satisfaction. Thus implementing
e-commerce has become a business necessity, as a company that fails to take advantage of
this technology will soon find themselves out of business.

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Benefits and Limitations of E-Commerce

E-Commerce is massively used in the world these days. It has various benefits and
limitations. Let’s discuss some of the benefits and limitations of using E-Commerce.
Benefits
 Easy to reach on the global market.
 We can easily choice the products that we want.
 Customers can easily select products from different providers.
 It helps to save our time.
 Easy to start and manage a business.
 No need of physical company set-ups.
 Low operational costs and better quality of services.
Limitations
 Fraud and online insecurity is increasing rapidly.
 Data privacy issues are increasing.
 Customer cannot test or check the services or goods.
 It is totally dependent on electronic technologies.
 There is no guarantee of product quality.
 Unnecessary rumour may spread with in a second all over the world.

Types of E-Commerce

Business to Business (B2B)

B2B E-Commerce refers to all the electronic transactions of goods and sales that are
conducted between two companies. This type of e-commerce typically explains the
relationship between the producers of a product and the wholesalers who advertise the
product for purchase to consumer. In the context of communication, business to business
refers to methods by which employees from different companies can connect with one
another, such as through social media. This type of communication between the employees
of two or more companies is called B2B communication.

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Business to Consumer (B2C )

B2C E-Commerce is the most common form of E-Commerce. It deals with electronic
business relationships between businesses and consumers. This e-commerce category
also enables businesses to develop a more personalized relationship with their customers.
Any business that trusts on B2C sales must maintain good relations with their customers.
B2C refers to the process of selling products and services directly between to consumers.
It is mainly used to refer to online retailers who sold products and services to consumers
through the Internet.

Consumer to Consumer (C2C)

This level of e-commerce encompasses all electronic transactions that take place between
consumers. Generally, these transactions are provided by online platforms but often are
conducted through the use of social media networks and websites. C2C represents a
market environment where one customer purchases goods from another customer using
a third-party business or platform to facilitate the transaction. C2C companies are a new
type of model that has emerged with E-Commerce technology.

Consumer to Business (C2B)

The C2B methodology completely transposes the traditional business-to-consumer (B2C)
model, where a business produces services and products for consumer consumption.
The C2B approach evolved from the growth of popular consumer-generated media and
content across different consumer segments, such as websites, blogs, podcasts, videos
and social networks. It is completely opposite to the concept of B2C where the companies
make goods and services available to the end consumers.

Business to Administration (B2A)

B2A E-Commerce category refers to all transactions between companies and public
administration. This is an area that involves many services, particularly in areas such as
social security, employment and legal documents. B2A e-commerce, also referred to as
B2G, is when a business provides an online service for the government, generally through
a website.

Consumer to Administration (C2A)

It is a popular E-Commerce category; C2A e-commerce encompasses all electronic
transactions between individuals and public administration. Examples of this include
taxes and scheduling an appointment using an online service. A C2A transaction can be
as simple as paying for parking tickets or ordering a new government ID. However, to be
considered a C2A E-Commerce transaction, this must be done online.

68 New Gateway to Computer Science Book -10

Let’s Review

 E-commerce is also known as electronic commerce or internet commerce.
 Ecommerce enables you to buy and sell products on a global scale, twenty-four
hours and 365 days.
 The primary goal of e-commerce is to bring the organizations closer to their actual
customers.
 E-Commerce is online shopping, which is defined as buying and selling of goods
through the internet on any device.
 E-commerce provides low operational costs and better quality of services.
 Unnecessary rumour may spread with in a second all over the world is the negative
aspects of e-commerce.
 B2B E-Commerce refers to all the electronic transactions of goods and sales that
are conducted between two companies.
 B2C deals with electronic business relationships between businesses and
consumers.
 C2C represents a market environment where one customer purchases goods from
another customer using a third-party business or platform to facilitate the
transaction.
 B2A E-Commerce category refers to all transactions between companies and
public administration.
 C2A e-commerce encompasses all electronic transactions between individuals
and public administration.

M-Commerce

Mobile commerce is popularly known as
M-commerce. It is a subset of E-Commerce. This
term was created in 1997 AD by Kevin Duffy.
It is essentially a way of carrying thousands
and millions of transactions in your pocket.
M-Commerce is the use of mobile phones to
conduct any type of business transaction. It is
the way of buying and selling of goods using
the mobile devices. These days most of the people are using their mobile devices more
often than their laptops or desktops to browse on the internet. There has been a huge
increase in transactions done through mobile devices in the last few years.

New Gateway to Computer Science Book -10 69

Due to the use of smartphone, online shopping has become very popular and trending
in Nepal these days. Every people has a mobile phone on their hand so just staying at a
corner of the room it is very easily to do the shopping of your desired products with lots of
choices. Even the suppliers feel comfortable to find you. So the future of E-commerce in
Nepal is very bright and charming. M-commerce has changed the thinking methodology
and the way of doing business by People through wireless technology. Besides, it is also
an integral part of the E-Commerce Platform, which ensures that marketplaces have
sufficient visions about their customer base. So, the current trends in the E-commerce
market boost future Mobile-Commerce or M-Commerce technology in Nepal.

Online Payment Mechanism

An online payment system is a way
of making transactions or paying
for goods and services through an
electronic medium, without the use
of cheques or cash. It’s also called an
electronic payment system or online
payment system. As the world advances
more with technology development, we
can see the rise of electronic payment
systems and payment processing devices. The electronic payment system has grown
gradually in our country Nepal these days. As this increase, the payment system by cheque
and cash is decreasing. One of the most popular payment forms online is credit and debit
cards. Besides them, there are also alternative payment methods, such as bank transfers,
electronic wallets, smart cards, etc.

An international online payment gateway from Nepal has just started from 2017 A.D.
which provides a safe, secure and easy payment solution. More and more successful
merchants are using this online payment system in Nepal to increase their business
potential. Online payment gateways work in fast and safe way, by allowing consumers
to pay directly using internet and their credit or debit card. By establishing an online
gateway portal from an application or website to the bank the sharing of information and
data becomes possible.

Some of the online payment service providers in Nepal are Esewa, Khalti, Ipay, IME Pay,
Qpay, PayWay, and so on.

70 New Gateway to Computer Science Book -10

Let’s Review

 Mobile commerce is popularly known as M-commerce.
 E-Commerce term was created in 1997 AD by Kevin Duffy.
 M-Commerce is the use of mobile phones to conduct any type of business
transaction.
 M-commerce has changed the thinking methodology and the way of doing
business by People through wireless technology.
 Online payment system is also called an electronic payment system or online
payment mechanism.
 The electronic payment system has grown gradually in our country Nepal these
days.
 An international online payment gateway from Nepal has just started from
2017 A.D.
 Online payment gateways work in fast and safe way, by allowing consumers to
pay directly using internet and their credit or debit card.
 Some of the online payment service providers in Nepal are Esewa, Khalti, Ipay,
IME Pay, Qpay, PayWay, etc.

Innovative Task

 Prepare a project report about any 5 popular e-commerce website those who are
providing e-commerce services in our country.

 Take a short audio interview with your school principal and teachers then present
in the class. (Sample questions are provided below. You can ask some more
questions as you like).

 What type of internet service you are using in your mobile?
 How long hours do you stay connect with internet?
 Do you know about internet banking?
 Are you using internet banking facility?
 Is there any apps installed in your mobile developed by the bank?
 Do you have SMS banking system?
 Do you have ATM card? Are you able to use it any time?
 Do you use credit card for shopping?
 Do you know about online-shopping? If yes, are you satisfied with their
services and product?
 Are you using any online payment system?
 What types of suggestions do you have for the students regarding the use
of technology?

New Gateway to Computer Science Book -10 71

Assignment

1. Select the best answer from the list of choices.

a. Which of the following is e-commerce service?

i. Online shopping ii. Uploading files

ii. Downloading files iv. Installing software

b. Which of the following is a benefit of e-commerce?

i. Low operational costs and better quality of services.

ii. Fraud and online insecurity is increasing rapidly.

iii. Data privacy issues are increasing.

iv. Customer cannot test or check the services or goods.

c. Which of the following is a limitation of e-commerce?

i. Easy to reach on the global market.

ii. It helps to save our time.

iii. Easy to start and manage a business.

iv. Customer cannot test or check the services or goods.

d. Which type commerce is mainly used to refer to online retailers who sold products
and services to consumers through the Internet?

i. B2B ii. B2C iii. C2C iv. C2B

e. When M-commerce term was created?

i. 1995 AD ii. 1996 AD iii. 1997 AD iv. 1998 AD

f. Which of the following is providing online payment system?

i. E-sewa ii. Khalti iii. IME Pay iv. All of them

2. Fill in the blanks with correct words / phrases.

a. E-commerce is also known as ………………………

b. The primary goal of ……………… is to bring the organizations closer to their
actual customers.

c. ……………………e-commerce refers to all the electronic transactions of goods
and sales that are conducted between two companies.

d. …………e-commerce category refers to all transactions between companies and
public administration.

e. E-Commerce term was created in …………………. AD.

72 New Gateway to Computer Science Book -10

f. ……………….. system is also called an electronic payment system or online
payment mechanism.

g. An international online payment gateway from Nepal has just started from
…………. A.D.

h. Mobile commerce is popularly known as ……………………

i. Online payment gateways work in fast and safe way, by allowing consumers to
pay ……………. using internet and their ……….. or debit card.

3. State whether the following statements are true or false.

a. Ecommerce enables you to buy and sell products on a global scale for a short time
period only.

b. E-Commerce is online shopping, which is defined as buying and selling of goods
through the internet on any device.

c. E-commerce provides high operational costs and better quality of services.

d. Unnecessary rumour may spread with in a second all over the world is the negative
aspects of e-commerce.

e. B2A deals with electronic business relationships between businesses and
consumers.

f. C2C represents a market environment where one customer purchases goods from
another customer using a third-party business or platform to facilitate the
transaction.

g. C2B e-commerce encompasses all electronic transactions between individuals
and public administration.

h. G-commerce is the use of mobile phones to conduct any type of business
transaction.

i. The electronic payment system has slow down gradually in our country Nepal
these days.

4. Answer the following questions.

a. What is E-Commerce? Explain in short.

b. What are the benefits and limitations of e-commerce?

c. What are the types of e-commerce? Define each in short.

d. What do you mean by m-commerce?

e. What is online payment system?

f. List out the various online payment services providers in Nepal.

g. List out the some popular e-commerce websites that are popularly used in our
country.

New Gateway to Computer Science Book -10 73

lesson Contemporary Technology

5

Learning Outcomes

At the end of this lesson, students will be able to:
 explain about cloud computing.
 tell the services of cloud computing.
 explain about artificial intelligence.
 tell about virtual reality.
 explain about e-governance.
 explain about mobile computing.
 tell about E-learning.
 explain about e-banking.
 Tell about Internet of Things (IOT).

The uses of ICT tools are rapidly increasing these days in the world. Latest and updated
devices and software programs are introducing in the world. In this age of globalizations,
all of us must be updated with the latest technologies that are being used in the world. In
Nepal, the uses of ICT tools are increasing then before. People are using latest ICT tools
and software programs in our country as well. Here, we are going to discuss some of the
contemporary technologies that are used these days.

Cloud Computing

The cloud computing means storing and accessing data
and programs over the Internet instead of storing on
secondary storage devices. The cloud is just an image
for the Internet. Cloud computing is the delivery of
different services through the Internet. These resources
include tools and applications like data storage, servers,
databases, networking, and software. Cloud computing
can be both public and private. Public cloud services
provide their services over the Internet with some

74 New Gateway to Computer Science Book -10

charges. Private cloud services only provide services to a certain number of people. These
services are a system of networks that supply hosted services. There is also a hybrid
option, which combines elements of both the public and private services.

Following are the services of cloud storage.
 Email
 Storage, backup, and data retrieval
 Creating and testing apps
 Analysing data
 Audio and video streaming
 Delivering software on demand

Cloud computing is still a new service but is being used by a number of different
organizations from big corporations to small businesses, non-profits to government
agencies, and even individual consumers.

Artificial Intelligence

Artificial Intelligence (AI) is the area of computer science focusing on creating machines
that can engage on behaviours, that human consider intelligent. It refers to the simulation
of human intelligence in machines that are programmed to think like humans and simulator
their actions. The term may also be applied to any machine that displays qualities related
with a human mind such as learning and problem-solving.

The applications for artificial intelligence are endless. The technology can be applied to
many different sectors and industries. AI is being tested and used in the healthcare industry
and different treatment in patients, and for surgical procedures in the operating room.
The various application areas where AI is currently being used include game playing,
speech recognition, natural language processing, computer vision, expert systems, neural
networks, robotics, etc. Some of the business functions where AI is used are finance,
medicine, manufacturing industry, transportation, telecommunication, aviation, etc.

Virtual Reality

Virtual Reality (VR) is the use of computer technology to create a simulated environment.
It is an artificial environment that is created with software and presented to the user in such
a way that the user suspends belief and accept it as a real environment. On a computer,
VR is primarily experienced through two of the five senses: sight and sound. The simplest

New Gateway to Computer Science Book -10 75

form of virtual reality is a 3D image that can be explored interactively at a personal
computer, usually by manipulating keys or the mouse so that the content of the image
moves in some direction or zooms in or out. This is called non-immersive VR. Virtual
reality can be the simulation of a real environment for training and education and the
development of an imagined environment for a game or interactive story.

Virtual Reality’s most immediately-recognizable component is the head-mounted display
(HMD). Human beings are visual creatures, and display technology is often the single
biggest difference between immersive Virtual Reality systems and traditional user
interfaces.

E-Governance

E-governance is the integration of ICT in all the
processes, with the aim of enhancing government ability
to address the needs of the general public. The basic
purpose of e-governance is to simplify processes for all,
i.e. government, citizens, businesses, etc. at national,
State and local levels. In short, it is the use of electronic
means, to promote good governance. It connotes the implementation of information
technology in the government processes and functions so as to cause simple, moral,
accountable and transparent governance. It entails the access and delivery of government
services, dissemination of information, communication in a quick and efficient manner.
E-governance can only be possible if the government is ready for it. It is not a one day
task, and so the government has to make plans and implement them before switching to it.

E-Governance offers many benefits and advantages for the government, corporate sector
and society. E-Governance facilitates better delivery of government services to citizens,
improved interactions with business and industry, citizen empowerment through access
to information, or more efficient government management. Through e-governance, the
government plans to raise the coverage and quality of information and services provided
to the general public, by the use of ICT in an easy, economical and effective manner. The
process is extremely complicated which requires, the proper arrangement of hardware,
software, networking and indeed re-engineering of all the processes to facilitate better
delivery of services.

E-governance has a great role to play, that improves and supports all tasks performed by
the government department and agencies, because it simplifies the task and increases the
quality of work.

76 New Gateway to Computer Science Book -10

Let’s Review
 The uses of ICT tools are rapidly increasing these days in the world.
 The cloud is just an image for the Internet.
 Cloud computing is the delivery of different services through the Internet.
 Public cloud services provide their services over the Internet with some charges.
 Private cloud services only provide services to a certain number of people.
 Artificial Intelligence (AI) refers to the simulation of human intelligence in
machines that are programmed to think like humans and simulator their actions.
 The various application areas where AI is currently being used include game
playing, speech recognition, natural language processing, etc.
 On a computer, VR is primarily experienced through two of the five senses: sight
and sound.
 E-governance can only be possible if the government is ready for it.
 E-Governance offers many benefits and advantages for the government, corporate
sector and society.

Mobile Computing

Mobile computing is a generic term that refers to a variety of devices that allow people to
access data and information from wherever they are. Mobile computing transports data,
voice, and video over a network via a mobile device. Mobile devices can be connected to
a local area network (LAN), Wi-Fi or wireless technology by connecting via a wireless
local area network (WLAN). Mobile phone services also provide mobile computing
through their service plans. Mobile computing devices are portable devices capable of
operating, executing, providing services and applications like a computing device. There
are many benefits to mobile computing including the ability to get directions, entertain,
do business, and more, including:
 Connectivity: You can stay connected to all sources at all times.
 Social Engagement: You can interact with a variety of users via the Internet.
 Personalization: You can tailor your mobile computing to your individual needs.

The following are the features of mobile computing
 It a portable device so it can be used anywhere easily and it can be used at any time.

New Gateway to Computer Science Book -10 77

 It saves time of accessing data and information.
 It helps to increase the productivity of the users.
 It can be used for remote access and cloud computing.
 It can include GPS (Global Positioning System) receiver from navigation.
 It has camera, speaker and microphone.
 It uses operating system such as android, iOS, Palm OS, windows, etc. for its
operations.
 It has the ability to share data and collaboration between users.

E-learning

E-learning is a new concept of delivering digital contents in learner oriented environment
using information and communication technology (ICT). It is the way of delivering the
digital content. E-learning refers to a learning system that we can obtain through the
internet using an electronic device. We also call it online learning or online education.
E-learning can be done using an Internet connection, a network, an Intranet, or a storage
disk. It uses a variety of media like audio, text, virtual environments, video and animation.
It is far better than classroom learning methods as it is a one-on-one learning method, it
is self-placed and it has an experiential-learning format.

E-learning, web-based training, internet-based training and computer-based training are
the next generation instruction methods being developed today. With E-learning, users
can immerse themselves in a three-dimensional environment to further enhance their
learning experience. It can be done anywhere and anytime as long as the user has the
proper hardware and internet connectivity.

Recently in Nepal, Nepal Open University has started its online academic courses for
bachelor’s degree, master’s degree, M.Phil. and even PhD through E-learning.

Advantages of e-learning:
 It is less expensive to produce.
 It maintains the consistency of content.
 It is very easy for customization.
 It can work from any location and any time.
 It can be updates easily and quickly.
 It reduces travel costs to attend learning events.
 It reduces or removes need for classroom/instructor infrastructure.
 It can be easily managed for large groups of students.

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E-Banking

Electronic Banking is an umbrella term for the process by which a customer may perform
banking transactions electronically without visiting an institution. All forms of banking
services and transactions performed through electronic means. E-banking includes the
systems that enable financial institution customers, individuals or businesses, to access
accounts, transact business, or obtain information on financial products and services
through a public or private network, including the internet.

E-banking is a safe, fast, easy and efficient electronic service that enables you access to
bank account and to carry out online banking services, 24 hours a day, and 7 days a week.
The customer using this facility can conduct transactional and non-transactional tasks
including:
 The customer can view account statements.
 The customer can check the history of the transactions for a given period by the
concerned bank.
 Bank, statements, various types of forms, applications can be downloaded.
 The customer can transfer funds, pay any kind of bill, recharge mobiles, etc.
 The customer can buy and sell on e-commerce platforms.
 The customer can invest and conduct trade.
 The customer can book transport, travel packages, and medical packages.

There are many different types of e-banking services which you can use for various bank
transactions. Let us discuss some of the most popular options.

Internet Banking

Internet Banking is a type of e-banking service which allows you to do several financial
and non-financial transactions through the internet. You can use your PC or laptop and an
internet connection to use this facility. With the help of Internet Banking, you can transfer
funds to another bank account, check your account statement, pay online bills, etc.

Mobile Banking

Most banks now also have an app for Mobile Banking. Just like the online portal of the
bank used for Internet Banking, you can use the app for many different types of banking
transactions. If you use an Android or iOS device, you can download the app of your bank
and use this facility. The apps can also be used for transferring funds, checking account
statements, locate the nearest ATM, and other banking services.

New Gateway to Computer Science Book -10 79

ATM

ATM or Automated Teller Machine is one of the most popular types of electronic
banking. The teller machine is also an electronic computerised telecommunication device
which enables you to withdraw funds, deposit funds, change PIN (Personal Identification
Number) and use other banking services.

Internet of Things (IOT)

Internet of Things is becoming an increasingly growing topic of discussion both in the
workplace and outside of it. The Internet of Things (IoT) is a system of interrelated
computing devices, mechanical and digital machines, objects, or people that are provided
with unique identifiers and the ability to transfer data over a network without requiring
human-to-human or human-to-computer interaction. The Internet of Things refers to
the ever-growing network of physical objects that feature an IP address for internet
connectivity, and the communication that occurs between these objects and other Internet-
enabled devices and systems.

IoT applications are used to address many real-world issues such as traffic jamming,
city services, economic development, citizen engagement, and public safety and security.
Smart cities often embed IoT sensors into the physical infrastructure, such as streetlights,
water meters and traffic signals, etc.

Let’s Review

 Mobile computing is a generic term that refers to a variety of devices that allow
people to access data and information from wherever they are.
 Mobile phone services also provide mobile computing through their service plans.
 Mobile computing devices are portable devices capable of operating, executing,
providing services and applications like a computing device.
 E-learning is a new concept of delivering digital contents in learner oriented
environment using information and communication technology (ICT).
 E-learning can be done using an Internet connection, a network, an Intranet, or a
storage disk.
 Electronic Banking is an umbrella term for the process by which a customer may
perform banking transactions electronically without visiting an institution.
 Internet Banking is a type of e-banking service which allows you to do several
financial and non-financial transactions through the internet.
 The Internet of Things refers to the ever-growing network of physical objects that
feature an IP address for internet connectivity, and the communication that occurs
between these objects and other Internet-enabled devices and systems.

80 New Gateway to Computer Science Book -10

Innovative Task

 Visit a bank nearby you and prepare a project report about what types of banking
facilities that they are provided to their customers.
 Take a short audio interview with any banker about the ATM card, Debit card,
Credit card, Remittance services, Online banking, SMS banking and present in
your class.

Assignment

1. Select the best answer from the list of choices.

a. What do you mean by contemporary technology?

i. Latest and update technology ii. Traditional type of technology

iii. Online technology iv. Phase out technology

b. Which of the following is the services of cloud computing?

i. Email ii. Audio and Video

iii. Creating and testing apps iv. All of them

c. Which of the following is related to AI?

i. Natural language processing ii. Operating system

iii. Hardware only iv. Software only

d. Which of the following is closer to E-Governance?

i. Providing computer ii. Proving water supply

iii. Providing E-Services iv. Providing loan

e. Which of the following is closer to E-learning?

i. General education ii. Online education

iii. Copyright iv. Offline education

f. Which of the following is E-Banking service?

i. Providing cheques ii. Providing voucher

iii. ATM card, SMS banking iv. All of them

2. Fill in the blanks with correct words / phrases.

a. The cloud is just an ……………. for the Internet.

b. .…………….. cloud services provide their services over the Internet with some
charges.

c. ……………………..refers to the simulation of human intelligence in machines
that are programmed to think like humans and simulator their actions.

New Gateway to Computer Science Book -10 81

d. On a computer, ……………… is primarily experienced through two of the five
senses: sight and sound.
e. ……………………. offers many benefits and advantages for the government,
corporate sector and society.
f. Mobile phone services also provide ……………… through their service plans.
g. ……………. is a new concept of delivering digital contents in learner oriented
environment using information and communication technology (ICT).
h. ……………….. is an umbrella term for the process by which a customer may
perform banking transactions electronically without visiting an institution.
3. State whether the following statements are true or false.
a. The uses of ICT tools are rapidly decreasing these days in the world.
b. Cloud computing is the delivery of different services through the Internet.
c. Public cloud services only provide services to a certain number of people.
d. The various application areas where AI is currently being used include game
playing, speech recognition, natural language processing, etc.
e. E-governance can only be possible if the government is not ready for it.
f. Mobile computing is a generic term that refers to a variety of devices that allow
people to access data and information from wherever they are.
g. E-learning can be done using an Internet connection, a network, an Intranet, or a
storage disk.
h. Internet Banking is a type of offline banking service which allows you to do
several financial and non-financial transactions through the internet.
4. Answer the following questions.
a. What is cloud computing? Write down the services of cloud storage.
b. What is artificial intelligence? Where it can be used?
c. Define virtual reality with its some supplication area.
d. What is e-governance? How its helps to the citizens?
e. Define mobile computing with its features.
f. What is e-learning? Write some advantages of e-learning.
g. Define e-banking. Write some e-banking services.
h. What are the uses of e-banking services?
i. Define internet banking and mobile banking.
j. Explain in short about IoT.

82 New Gateway to Computer Science Book -10

Lesson

6 Computer Number System

Learning Outcomes

At the end of this lesson, students will be able to:
 describe the history of number system.
 tell the types of computer number system.
 convert different numbers into different bases.
 do the addition, subtraction, multiplication and division of binary numbers.

When we type some letters or words, the computer translates them in numbers as
computers can understand only numbers. A computer can understand positional number
system where there are only a few symbols called digits and these symbols represent
different values depending on the position they occupy in the number. Number systems
use different number bases. A number base indicates how many different digits are
available when using a particular numbering system. For example, the base of decimal
number is 10, which means it uses ten digits: 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. The base of
binary number is 2, which means that it uses two digits that are 0 and 1.

A number system in base r or radix r uses unique symbols for r digits. One or more digits
are combined to get a number. The base of the number decides the valid digits that are
used to make a number. In a number, the position of digits starts from the right-hand side
of the number. The right most digits has position 0, the next digit on its left has position1,
and so on. The digits of a number have two kinds of values they are face value and
position value.

The face value of a digit is the digit located at that position. For example, in decimal
number 87, face value at position 0 is 7 and face value at position 1 is 8.

Types of Number System

 Binary number system
 Octal number system
 Decimal number system
 Hexadecimal number system

New Gateway to Computer Science Book -10 83

Binary Number System

A Binary number system has only two digits that are 0 and 1. Every number (value)
represents 0 and 1 in this number system. The base of binary number system is 2, because
it has only two digits. (10101)2, (111000)2, (101110)2, etc. are the examples of binary
number system. This is a positional notation numbering system. Each position in a binary
number system represents a positive power of 2 i.e. 20, 21, 22, 23, 24, 25 and so on. The
position value and quantity of a digit at different positions in a number are shown in the
given table.

Position 3210

Position Value 23 22 21 20

Quantity 8421

Decimal Number System

Decimal number system has only ten (10) digits from 0 to 9. Every number (value)
represents 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 in this number system. The base of decimal number
system is 10, because it has only 10 digits. This is a positional notation numbering system.
Each position in a decimal number system represents a positive power of 10 i.e. 100, 101,
102, 103, 104, 105 and so on. (55)10, (799)10, (8459)10, etc. are the examples of decimal
number system. The position value and quantity of a digit at different positions in a
number are shown in the given table.

Position 3210

Position Value 103 102 101 100

Quantity 1000 100 10 1

Octal Number System

Octal number system has only eight (8) digits from 0 to 7. Every number (value) represents
0, 1, 2, 3, 4, 5, 6 and 7 in this number system. The base of octal number system is 8,
because it has only 8 digits. (27)8, (760)8, (5473)8, etc. are the examples of octal number
system. This is a positional notation numbering system. Each position in a octal number
system represents a positive power of 8 i.e. 80, 81, 82, 83, 84, 85 and so on. The position
value and quantity of a digit at different positions in a number are shown in the given
table.

Position 3210

Position Value 83 82 81 80

Quantity 512 64 8 1

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Look at the decimal-octal-binary conversion table below.

Decimal Octal Binary

0 0 000

1 1 001

2 2 010

3 3 011

4 4 100

5 5 101

6 6 110

7 7 111

Hexadecimal Number System

A hexadecimal number system has sixteen (16) alphanumeric values from 0 to 9 and
A to F. Every number (value) represents 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E and F
in this number system. The base of hexadecimal number system is 16, because it has
16 alphanumeric values. Here A is 10, B is 11, C is 12, D is 13, E is 14 and F is 15.
This is a positional notation numbering system. Each position in a hexadecimal number
system represents a positive power of 16 i.e. 16°, 161, 162, 163, 164, 165 and so on. (985)16,
(DAD1)16, (1F73)16, etc. are the examples of hexadecimal number system. The position
value and quantity of a digit at different positions in a number are shown in the given
table.

Position 3210

Position Value 163 162 161 160

Quantity 4096 256 16 1

Look at the decimal-hexadecimal-binary conversion table below.

Decimal Binary Hexadecimal
0 0000 0
1 0001 1
2 0010 2
3 0011 3
4 0100 4
5 0101 5
6 0110 6
7 0111 7
8 1000 8

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9 1001 9

10 1010 A

11 1011 B

12 1100 C

13 1101 D

14 1110 E

15 1111 F

Let’s Review

Number system with their base, used digits and example.

Number System Base Used Digits Example
Binary 2 0 and 1
Octal 8 (10101111)2
Decimal 10 0, 1, 2, 3, 4, 5, 6 and 7 (755)8
Hexadecimal 16 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9 (7921)10

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, (D1FB)16
A, B, C, D, E and F

Number Conversion

Converting from Binary, Octal and Hexadecimal into Decimal

We use the following steps to convert a number in any other base to a base 10 (decimal)
number:

Step1: Determine the positional value of each digit (this depends on the position of the digit
and the base of the number system).

Step 2: Multiply the obtained value (in step 1) by the digits in the corresponding place.

Step 3: Sum up the products calculated in step 2. The total is the equivalent value in
decimal.

Binary to Decimal

Example: Convert (11011)2 into (? )10
Digits 1 1 0 1 1

Power of (2) 24 23 22 21 20

= (1 × 24) + ( 1 × 23) + (0 × 22) + ( 1 × 21) + ( 1 × 20)

= 16 + 8 + 0 + 2 + 1

= 27

Thus: (11011)2 = (27)10

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Octal to Decimal

Example: Convert (417)8 into (?)10
Digits 4 1 7

Power of (8) 82 81 80

= (4×82) + (1×81) + ( 7 × 80)

= (4×64) + (1× 8) + (7×1)

= 256 + 8 + 7

= 271

Thus: (417)8 = (271)10
Hexadecimal to Decimal

Example: Convert (AB1)16 into (?)10

Digits A (10) B(11) 1

Power of (16) 162 161 160

= (10×162) + (11×161) + (1×160)

= (10×256) + (11×16) + (1×1)

= 2560 + 176 + 1

= 2737

Thus: (AB1)16 = (2737)10
Converting from Decimal to Binary, Octal and Hexadecimal

We use the following steps to convert a base 10 (decimal) number to a number in any
other base:

Step 1: Divide the decimal number by the value of the new base.

Step 2: Record the reminder from step 1 as the rightmost digit (least significant digit) of the
new base number.

Step 3: Divide the quotient of the previous division by the new base.

Step 4: Record the remainder from step 3 as the next digit (to the left) of the new base
number.

Step 5: Repeat steps 3 and 4, recording remainders from right to left, until the quotient
becomes zero in step 3.

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Decimal to Binary

Example 1: Convert (104)10 into (?)2 Example 2: Convert (90)10 into (?)2
2 104 Remainder 2 90 Remainder

2 52 0 2 45 0

2 26 0 2 22 1

2 13 0 2 11 0

26 1 25 1

23 0 22 1

21 1 21 0

0 1 0 1

=1101000 = 1011010

Thus: (104)10 = (1101000)2 Thus: (90)10 = (1011010)2

Decimal to Octal

Example 1: Convert (1341)10 into (?)8 Example 2: Convert (1910)10 into (?)8
8 1341 Remainder 8 1910 Remainder

8 167 5 8 238 6

8 20 7 8 29 6

82 4 83 5

0 2 0 3

= 2475 = 3566

Thus: (1341)10 = (2475)8 Thus: (1910)10 = (3566)8
Decimal into Hexadecimal:

Example 1: Convert (494)10 into (?)16 Example 2: Convert (945)10 into (?)16

16 494 Remainder 16 945 Remainder

16 30 14(E) 16 59 1

16 1 14(E) 16 3 11 (B)

0 1 03

= 1EE = 3B1

Thus: (494)10 = (1EE)16 Thus: (945)10 = (3B1)16

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Binary into Octal

Step 1: Separate the digits of a given binary number into group of 3 digits from right to
left.

Step 2: Add 0’s to the left, if the last group doesn’t contain 3 digits.

Step 3: Find the equivalent octal number for each group.

Step 4: Write the all groups octal numbers together to determine the value in octal.

Example: 1 Convert (101010)2 into octal

Binary number: 101010

Binary grouping of 3 digits from right to left: 101 010

Octal equivalent: 52

Thus: (101010)2 = (52)8 001 111 000 111
Example: 2 Convert (1111000111)2 into octal 1 707

Binary number: 1111000111
Binary grouping of 3 digits from right to left:
Octal equivalent:

Thus: (1111000111)2 = (1701)8
Octal into Binary

Step 1: Separate the digits of the given octal number.

Step 2: Find the equivalent binary number for each digit of octal number.

Step 3: Write the all group’s binary numbers together, maintaining the same group order
provides the equivalent binary for the given octal number.

Example: 1 Convert (175)8 into binary 1 75
001 111 101
Octal number: 175
Individual octal digit:
Binary equivalent of individual octal digit:

Thus: (175)8 = (001111101)2 7 631
Example: 2 Convert (7631)8 into binary 111 110 011 001

Octal number: 7631
Individual octal digit:
Binary equivalent of individual octal digit:

Thus: (7631)8 = (111110011001)2

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Hexadecimal into Octal

Step 1: Separate the digits of the given hexadecimal number.

Step 2: Find the equivalent binary number for each digit of hexadecimal number.
Add 0’s to the left if any of the binary equivalent is less than 4 digits.

Step 3: Write the all groups binary numbers together, maintaining the same group.

Step 4: Separate the binary digits into groups, each containing 3 digits from right to left.
Add 0’s to the left, if the last group contains less than 3 digits.

Step 5: Find the octal equivalent for each group.

Step 6: Write all octal equivalent of each digit together.

Example: 1 Convert (AC2)16 into octal A C2

Hexadecimal number: AC2 1010 1100 0010
Binary equivalent of individual hexadecimal digit:
Writing all the groups of binary numbers together: 101011000010
Grouping with 3 digits for octal equivalent:
Octal equivalent: 101 011 000 010

5 3 02

Thus: (AC2)16 = (5302)8 B 5A
Example: 2 Convert (B5A)16 into octal
1011 0101 1010
Hexadecimal number: B5A
Binary equivalent of individual hexadecimal digit: 101101011010
Writing all the groups of binary numbers together:
Grouping with 3 digits for octal equivalent: 101 101 011 010
Octal equivalent:
5 5 32

Thus: (B5A)16 = (5532)8
Octal into Hexadecimal
Step 1: Separate the digits of the given octal number.

Step 2: Find the equivalent binary number for each digit of octal number. Add 0’s to the
left if any of the binary equivalent is shorter than 3 digits.

Step 3: Write the all groups binary numbers together, maintaining the same group order.

Step 4: Separate the binary digits into groups, each containing 4 digits from right to left.
Add 0’s to the left, if the last group contains less than 4 digits.

Step 5: Find the hexadecimal equivalent for each group.
Step 6: Write all hexadecimal equivalent of each digit together.

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Example: 1 Convert (753)8 into hexadecimal 75 3

Octal number: 753 111 101 011
Binary equivalent of individual octal digit:
Writing all the groups of binary numbers together: 111101011
Grouping with 4 digits for hexadecimal equivalent:
Hexadecimal equivalent: 0001 1110 1011

1 14(E) 11(B)

Thus: (753)8 = (1EB)16 52 3
Example: 2 Convert (523)8 into hexadecimal
101 010 011
Octal number: 523
Binary equivalent of individual octal digit: 101010011
Writing all the groups of binary numbers together:
Grouping with 4 digits for hexadecimal equivalent: 0001 0101 0011
Hexadecimal equivalent:
153

Thus: (523)8 = (153)16
Binary into Hexadecimal

Step 1: Separate the digits into groups from right to left. Each group should contain 4
digits of binary number.

Step 2: Add 0’s to the left, if the last group has less than 4 digits.

Step 3: Find the equivalent hexadecimal number for each group.

Step 4: Write the all groups hexadecimal numbers together, maintaining the group order
provides the equivalent hexadecimal number for the given binary.

Example: 1 Convert (1010000111)2 into hexadecimal

Binary number: 1010000111

Binary grouping of 4 digits from right to left: 0010 1000 0111
87
Hexadecimal equivalent: 2

Thus: (1010000111)2 = (287)16

Example: 2 Convert (1111101011011111)2 into hexadecimal

Binary number: 1111101011011111

Binary grouping of 4 digits from right to left: 1111 1010 1101 1111
13 (D) 15 (F)
Hexadecimal equivalent: 15 (F) 10 (A)

Thus: (1111101011011111)2 = (FADF)16

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Hexadecimal into Binary
Step 1: Separate the digits of the given hexadecimal, if more than 1 digit.
Step 2: Find the equivalent binary number for each digit of hexadecimal number.
Step 3: Add 0’s to the left if any of the binary equivalent is less than 4 digits.
Step 4: Write the all groups binary numbers together, maintaining the same group order
provides the equivalent binary for the given hexadecimal.

Example: 1 Convert (A01)16 into binary A 01
1010 0000 0001
Binary number: A01
Binary grouping of 4 digits from right to left: D AF
Hexadecimal equivalent: 1101 1010 1111
Thus: (A01)16 = (101000000001)2
Example: 2 Convert (DAF)16 into binary

Binary number: DAF
Binary grouping of 4 digits from right to left:
Hexadecimal equivalent:

Thus: (A01)16 = (110110101111)2

Binary Arithmetic

The arithmetic operations like addition, subtraction, multiplication and division performed
on the number is called binary arithmetic.

Binary Addition

It works in the same way, except that only 0’s and 1’s can be used, instead of the whole
range of 0-9. This actually makes binary addition much simpler than decimal addition.

The rules of binary additions are as follows:

0+0=0 As an example of binary addition we have,

0+1=1 101
+1 0 1
1+0=1
1 0 1 0
1 + 1 = 0 (plus a carry of 1 to next higher
column

Carry overs are performed in the same manner as in decimal arithmetic. Since 1 is the
largest digit in binary number system, any sum greater than 1 requires a digit to be carried
over. In the above example to add the number (1+1), we first consider the “ones” column

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and calculate 1 + 1, which (in binary) results in 10. We “carry” the 1 to the “tens” column,
and the leave the 0 in the “ones” column.

Moving on to the “tens” column, we calculate 1 + (0 + 0), which gives 1. Nothing “carries”
to the “hundreds” column, and we leave the 1 in the “tens” column.

Another example of binary addition

1011
+ 1011
10110

Note that in the “tens” column, we have 1 + (1 + 1), where the first 1 is “carried” from the
“ones” column. Recall that in binary, 1 + 1 + 1 = 10 + 1 = 11

Add the following numbers

a. 1 0 1 1 1 1 + 1 0 1 1 0 b. 1 1 0 1 1 1 + 1 1 1 1 1
110111
101111 +1 1 1 1 1
+1 0 1 1 0
1000101 1010110

Binary Subtraction

Binary subtraction is also similar to that of decimal subtraction with the difference that
when 1 is subtracted from 0, it is necessary to borrow 1 from the next higher order bit and
that bit is reduced by 1.
The rules of binary subtraction are as follows:

0-0=0

1-0=1

1-1=0

0 - 1 = 1 with a borrow of 1 from the next column.

Subtract the following numbers:

a. 101 from 1001 b. 111 from 1000

Solution: Solution:
101 from 1001 111 from 1001

1 Borrow 1 Borrow

1001 1000
−1 0 1
−1 1 1
0100 0001

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Binary Multiplication

Multiplication in binary number system also follows the same general rules as in decimal
number system.

The rules of binary multiplication are as follows:
0x0=0
0x1=0
1x0=0

1x1=1

Multiply the following numbers:

a. 11011 by 101 b. 101 by 111

Solution: Solution:
11011 101
×101
11011 ×111
101
00000
+1 1 0 1 1 101
10000111 +1 0 1
100011

Binary Division
The rules of binary dicision are as follows:
0 ÷ 0 = Divide by zero error
0 ÷ 1 = 0
1 ÷ 0 = Divide by zero error
1 ÷ 1 = 1
Note that since division by 0 in any number system is meaningless, computers deal with
this problem by raising an error condition called ‘Divide by zero’ error.
Some rules for binary division are listed below.
Step 1 : Start from the left of the dividend.
Step 2 : Perform a series of subtractions, in which the divisor is subtracted from the
dividend.
Step 3 : If subtraction is possible, put a 1 in the quotient and subtract the divisor from the

corresponding digits of dividend.
Step 4 : If subtraction is not possible, record a 0 in the quotient.

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Step 5 : Bring down the next digit to add to the remainder digits. Proceed as before in a
manner similar to long division.

Divide the following numbers:

a. 1011 divided by 11. b. 10010 divided by 11
11 (Quotient)
1 1 0 (Quotient)
11)1011 11) 1 0 0 1 0
-11
101 −1 1
-11
10 (Remainder) 11
− 11

00
−0

0 (Remainder)

So that, in the above example ‘a’ the quotient is 11 and remainder is 10. Like this in the
above example ‘b’ the quotient is 110 and remainder is 0.

Innovative Task

 Prepare a decimal-octal-binary conversation table and decimal-hexadecimal-
binary conversation table in a chart paper and submit to your teacher as your
project work.

Assignment

1. Select the best answer from the list of choices.

A. A positional number system that utilizes the symbols 0 and 1.

i. Decimal number system iii. Binary number system

ii. Octal number system iv. Hexadecimal system

B. The decimal equivalent of binary number (1100110)2 is:

i. (102)10 iii. (103)10

ii. (104)10 iv. (105)10

C. The hexadecimal digits are 0 to 9 and A to:

i. E iii. F

ii. G iv. H

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D. A combination of 8 bits.

i. 0 and 1 iii. Byte

ii. Byte iv. Nibble

E. A unit of computer memory or data storage capacity equal to 1024 MB.

i. Petabyte (PB) iii. Megabyte(MB)

ii. Gigabyte(GB) iv. Kilobyte(KB)

F. A unit of information or computer storage equal to 1024 ZB.

i. Yota byte(YB) iii. Megabyte(MB)

ii. Gigabyte(GB) iv. Kilobyte (KB)

2. Fill in the blanks with correct words / phrases.

a. The……….. number system is a number system in which each symbol represents
the same value, regardless of its position in the number.

b. ………..is positional number system having base 2.

c. The ………..is used in computing as a simple means of expressing binary
quantities.

d. A ……….can represent a single character, such as a letter, a digit, or a punctuation
mark.

e. ………is a unit of computer memory or data storage capacity equal to 1024 KB.

f. A …….is a unit of information or computer storage equal to 1024 ZB.

3. State whether the following statements are true or false.

a. Number system is an organized and systematic way of representing numbers.

b. The most common positional number system is the Roman number system.

c. Binary number system is a positional number system having base 10.

d. Decimal number system is a positional number system having base 10.

d. The combination of two bits is called a crumb.

e. Yottabyte is a unit of computer memory or data storage capacity equal to 1024 PB.

4. Convert the following as indicated.

a. (1010111)2 into Decimal
b. (11001111)2 into Octal
c. (110001100)2 into Hexadecimal

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d. (7541)8 into Decimal
e. (5432)8 into Binary
f. (3102)8 into Hexadecimal
g. (901)10 into Binary
h. (971)10 into Octal
i. (109)10 into Hexadecimal
j. (AO1F)16 into Binary
k. (B89)16 into Decimal
l. (DAD101) 16 into Octal
5. Do the following activities given below.
a. (10101) + (1101)
b. (1001) + (101) + (11)
c. (11101) – (11001)
d. (1001010) – (110101)
e. (1101) × (11)
f. (1110101) ÷ (101)
g. (1011) × (11) + (10101)
h. (1010) – (11) × (11)
i. (101010) – (111) ÷ (11)
j. (111) + (111) – (10)

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Database Management
System

Unit

2

This unit cover the following lesson:

Lesson 7: Database management system (MS-ACCESS)

Lesson Database Management System
MS-Access
7

Learning Outcomes

At the end of this lesson, students will be able to:
 define the terms such as data, database, information, etc.
 tell about the database management system.
 write the advantages and disadvantage/s of database.
 tell about the elements of database.
 discuss about RDBMS.
 discuss the objects of MS-Access.
 work with Microsoft Access.

Database is an organized collection of related information or data, where we can store
organized information for multiple purposes. A telephone directory is one of the most
common examples of database, where the names of telephone subscribers are given in an
alphabetical order. Likewise dictionary, school student’s record, teacher’s salary record
etc. are also given. Databases are structured to facilitate storage, retrieval, modification,
and deletion of data in conjunction with various data-processing operations. A database
consists of a file or a set of files that can be broken down into records, each of which
consists of one or more fields. DBMSs can manage any form of data including text,
images, sound and video. Database and file structures are always determined by the
software.

Data and Information

Data are raw, unorganized facts that need to be processed which have no meaning. When
data are processed, organized, structured or presented in a given context to make it
useful that is called information. Here, we can say data are meaningless but information
is meaningful. Data are the source of information. Without data information cannot be
formed.

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