Vedanta Let's Log in Computer Class 10 (Revised).indd

Approved by the Government of Nepal, Ministry of Education, Science and Technology,
Curriculum Development Centre, Sanothimi, Bhaktapur as an Additional Learning Material

vedanta

Computer Science

Book

Authors:

Sushil Upreti Sunil Kumar Gharti

vedanta

Vedanta Publication (P) Ltd.
jb] fGt klAns;] g k|f= ln=

Vanasthali, Kathmandu, Nepal
+977-01-4982404, 01-4962082
[email protected]
www.vedantapublication.com.np

vedanta Book

Let's Log in

Computer Science

All rights reserved. No part of this publication may be reproduced, copied or
transmitted in any way, without the prior written permission of the publisher.

Authors: Sunil Kumar Gharti
Sushil Upreti

© Vedanta Publication (P.) Ltd.

Design: Manoz Manohar
First Edition: BS 2077 (2020 AD)
Second Edition: BS 2078 (2021 AD)

Printed in Nepal

Published by:

Vedanta Publication (P) Ltd.

j]bfGt klAns;] g k|f= ln=

Vanasthali, Kathmandu, Nepal
+977-01-4982404, 01-4962082
[email protected]
www.vedantapublication.com.np

Preface

This is the age of information. Information Technology
has undoubtedly invaded all walks of life to such an extent
that computer and information literacy has become the
fundamental part of our daily activities. Computer Science
is now an essential addition to the school curriculum at all
levels.

Vedanta Let’s Log in (A course in Computer Science)
is a series of ten books on Computer Science for basic
and secondary level students, designed for the need of
new generation to help acquire knowledge on the theory,
application and programming aspects of computing. This
series is based on the new syllabus of Computer Science,
designed and approved as per the curriculum prescribed
by Curriculum Development Center, Ministry of Education,
Government of Nepal.

The series covers the history of computer, its accessories,
applications and programming in LOGO and QBASIC in
a step-by-step and graded manner following logical and
scienti ic approach. Concept of graphic and web design is
also illustrated with many practical examples. This series not
only assists the students and the teachers in the class but also
incorporates latest information and developments in IT with
the present need of the students in Nepal. It also provides
other enthusiasts and learners with the skill and knowledge
to cope up with the growing demand of IT skills in market
and daily life.

We earnestly hope that the students would ind the journey
through this series an enjoyable experience and gain a sound
working knowledge on the basic aspects of computing and
information technology.

As far as possible, we have sincerely put in our efforts to
make the book error free. However, there is always scope
for improvement. Constructive criticism and feedback are
always welcome.

Authors

Content 5
6
Group A 47
1 Networking and Telecommunication 61
1.1 Networking and Telecommunication 84
1.2 Ethical and Social Issues in ICT 96
1.3 Computer Security 109
1.4 E-Commerce
1.5 Contemporary Technology 125
1.6 Number System 126
Group B 132
2 Database Management System 145
2.1 Introduction to Database Management System 152
2.2 Creating Database Using Microsoft Access 163
2.3 Entering and Editing Data 166
2.4 Querying Database
2.5 Creating and Using Forms 173
2.6 Creating and Printing Reports 174
Group C 181
3 Programming in QBASIC 212
3.1 Review of QBASIC Programming
3.2 Modular Programming 233
3.3 File Handling in QBASIC 234
Group D 275
4 Structured Programming in C 278
4.1 Structured Programming in C

Abbreviation
SEE (Model Question)

Vedanta Let’s Log in Computer Science | Book 10 Group A

Unit

1

Networking and
Telecommunication

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Unit Networking and

1.1 Telecommunication

Introduction

Communication is the process of sharing news, views, ideas, and information from
one place, person, or group to another in an understandable manner. We practice
various forms of communications in our daily life. The lecture of a teacher in a
classroom, the progress reports of students shared by the school with parents, the
conversations of friends over the telephone, and an e-mail exchange with a relative
are all examples of communications. In this lesson, we discuss some basic concepts
of communications.

Components of Communication Communicating

There are mainly four components of communication:
i. Sender (the origination end

of communication)
ii. Medium (material through

which the content of
communication transfers
from origin to destination)
iii. Receiver (the targeted end
of communication)
iv. Feedback (the receiver
responds in some way and
signals the response to the
sender)

Types of Communication

There are different types of communications. In this lesson, we discuss three
common types of communication.

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1. Simplex Communication

In simplex communication, the message is transmitted in only one direction.
Radio broadcast, and television programs are examples of simplex communication.

Radio TV

2. Half Duplex Communication

In Half Duplex communication the message can be transmitted in both
ways but not simultaneously. Generally, a mechanism is used to decide the
direction of communication. When communication is taking place in one direction,
communication in other direction is not possible at the same time. The direction
of communication can be switched then to make communication in other direction
possible. The walkie-talkie set used by the security personnel is an example of
Half Duplex communication.

Walkie-talkie

3. Full Duplex Communication:

In Full-Duplex (also called Duplex)
communication, transmission of message is
possible in both directions simultaneously.
Message can be transmitted in both the
directions at the same time. Talking over the

Talking in phone

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telephone is the example of Full Duplex Communication. Chatting over internet is
another example of full-duplex communication.

Telecommunication

Transmitting message over a distance using wired or wireless media is called
telecommunication. Telecommunication has brought about a revolution in the
field of communication. It has made the communication quick, convenient,
reliable, and cost-effective. The message can travel very long distance in a verity
of formats. Different types of data and signal can travel over the media used
for telecommunication. Two major types of signals travel in the communication
channel/media – digital signal and analog signal.

Analog and Digital Signal

A signal is an electrical impulse or radio wave sent or received with an intention
to transmit data or information. When data are propagated in the form of electrical
signals, the signals may be in either digital or analog form. Analog signal is
represented by a continuously varying physical effect or measurement. Analog
signal passes through all the values in the range. On the other hand, a digital
signal is represented as a series of binary digits (0 and 1). Digital signals have two
amplitude levels called nodes. The value of the digital signal is specified as one of
the two possibilities - 1 or 0, HIGH or LOW, TRUE or FALSE.

Analog signal

1

0
100101101

-1

Digital signal

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Computer-generated data are digital, whereas telephone lines carry analog signals.
When digital data has to be transmitted on an analog facility, it must be converted
to analog form first. Modulation is the technique of converting a digital signal
into analog form, and demodulation is the reverse process of converting an analog
signal to digital form.

Data Communications with standard Telephone Lines and
Modems

Modems

A special device called modem (modulator/demodulator) is used to carry out the
process of modulation and demodulation (conversion of digital data to analog
form and vice-versa). Millions of homes and businesses still have analog telephone
lines. Attaching a computer to an analog telephone line requires a modem. A
computer uses digital signal that consists of ON / OFF pulses representing 1 and
0. The modem is required to translate these digital signals into analog signals that
can travel over telephone lines and back to digital form at the receiving end. In
its modulation phase, the modem turns the computer’s digital signals into analog
signals, which are then transmitted across the phone line. The reverse takes place
during its demodulation phase; the modem receives analog signals from the phone
line and converts them into digital signals for the computer.
There are many types of modems used to translate signal transmitted in over
different types of media such as Cable Modem, ADSL (Asymmetric Digital
Subscriber Line) Modem, Wireless Modems, Fiber Optic Modem, etc. A modem’s
transmission speed is measured in bits per second (bps).

Modems

Modulator/Demodulator

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Bandwidth

In computer networks, bandwidth is often used as a synonym for data transfer
rate - the amount of data that can be carried from one point to another in a given
time period (usually a second). It is analogous to a road’s width. Wider a road, the
more traffic it can handle in a given time. Similarly, higher the bandwidth of a
communication channel, the more data it can transfer in a given time. Bandwidth
is measured in bits per second (bps). For instance, 4G GSM (Global System for
Mobile Communications) wireless network has bandwidth up to 20Mbps or more
which is ten times the bandwidth of 3G, which is up to 2Mbps.

Low and High Bandwidth

Introduction of Computer Network

The modern era of computing started with mainframe and minicomputers. These
computers used a central system and many terminals. The central system housed
resources like processor, memory and storage to serve all the terminals. The
terminals were just the means of an interface to the user (Input and Outputs). All
the processing, storage, and even printing for users in all the terminals were done
in the central unit. This type of computing is called centralized computing. This
type of computers is highly expensive and only big institutions like universities,
business houses and government departments could afford them.

Mainframe computer Mini computer

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In the beginning of the 1980s, IBM (later followed by Apple Inc.) made smaller
models of computers which were designed for one user. There were enough resources
– processor, memory, storage to serve one user. This type of computing is called
personalized computing. These types of computer systems were comparatively much
cheaper and computers became affordable for small business and individuals. The
major disadvantage of this type of computing was sharing of data and resources
like storage and printers.

Personalized computer

Then the system of connecting individual computers with some medium came to
make sharing of resources and data possible. The interconnection of autonomous
computers and other devices with the wired or wireless medium for sharing
data and resources is called computer network. In a computer network, the
individual computers have their own resources for processing, memory, and storage
of data, and can work independently if disconnected from the network.

Computer network

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Advantages of Computer Network

Sharing and transferring files within Networks.
On a network, it allows for easier upgrading of the program and data on one

single server, instead of updating it on individual workstations.
Resources such as storage, printers, fax machines, and modems can be shared.
Due to this, the cost of computing is reduced to each user as compared to the
development and maintenance of each single computer system.
Communication is easy and fast

Disadvantages of Computer Network

Networks can be expensive to set up.
Networks are vulnerable to security problems.
Skilled human resources are required to manage and supervise network.
The File Server needs to be a powerful computer, which often means that it
is expensive.

Types of Computer Networks

There are different types of networks. The networks are classified based on
scope and the role of individual computer in the network. To understand different
types of networks and how they operate, you need to know how networks are
structured. There are two main types of networks: Local Area Networks (LANs)
and Wide Area Networks (WANs).

Local Area Network (LAN)

A LAN (Local Area Network) is a group of computers and associated devices that
share common communication lines or wireless links. Typically, connected devices
share the resources within a small geographic area (for example, within an office
building). Any network that exists within a single building, or even a group of
adjacent buildings, is considered a LAN. A LAN is not a system that connects to the
public environment (such as internet) using phone or data lines.
Most LANs connect workstations and personal computers. Each node (individual
computer) in a LAN has its own CPU with which it executes programs, but it is also
able to access data and devices anywhere in the LAN. This means that many users
can share expensive devices such as laser printers, and data. Users can also use

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the LAN to communicate with each other, by sending e-mail or engaging in chat
sessions. The characteristic features of LAN are:

Local Area Network (LAN)

a) Scope

LAN is confined in small geographical areas such as a room, a building, or a
premise, or an organization.

b) Dedicated Connection

LAN has a dedicated connection (Wired or Wireless) explicitly installed. It
does not share connection media of other services such as local telephone company
or cable operator.

c) Topology

LAN has to be connected in a layout that can be defined as one of the standard
topologies. That is why, theoretically, it is said that two computers cannot form a
LAN as we cannot categorize the connection between two computers as one of the
defined topology.

Wide Area Network (WAN) China ISP
Nepal
A wide area network (WAN) is the
type of network which covers relatively Singapore
larger geographical area than a LAN
or MAN, often a country or continent.

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For example, a company may have its corporate headquarters and manufacturing
plant in one city and its marketing office in another city. Each site needs resources,
data, and programs locally, but it also needs to share data with the other sites. To
accomplish this sort of data communication, the company can attach devices that
connect over public utilities to create a WAN.

Wide Area Network (WAN)

These remote LANs are connected through a telecommunication network or via
the internet through an Internet Service Provider (ISP) that contracts with the
telecommunication networks to gain access to the internet’s backbone.

Metropolitan Area Network (MAN)

Between the LAN and WAN structures, you find hybrid networks such as campus
area networks (CANs) and metropolitan area networks (MANs). The metropolitan
network is a large-scale network that connects multiple corporate LANs together.
MANs usually are not owned by a single organization: their communication devices
and equipment are usually maintained by a group or single network provider that
sells its networking services to corporate customers. MANs often take the role of
a high-speed network that allows for the sharing of regional resources. MANs also
can provide a shared connection to other networks using a WAN link.

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Network Architecture

Networks can be categorized based on the role individual PCs play in terms of
hierarchy and security interaction. Some networks use client-server architecture
and others use peer-to-peer architecture.

Client-Serverer Networks

One of the most popular types of server-
based network is the client-server network,
where individual computers share resources
and services of the central server. This Clients Internet
arrangement requires special software for Clients

the nodes and the server. In the client- Clients
serverer model one or more computers
provide services to other computers in the Server

network. The servers provide different types
of services to the client computers. There
can be different types of servers depending on the type of service they provide. A
server which provides facility to store files is called a file server. A server which
manages outgoing and incoming mails in the network is called a mail server.
There can be a print server, web server, FTP server, and so on.

Rcelqieunetst by Database
Response Printer

Server Scanner

Client / Server Network Architecture

Peer-to-Peer Networks:

In a peer-to-peer network (abbreviated as “P2PN” also called a workgroup), all
nodes in the network have equal relationships to each other, and all have similar
type of software that support the sharing of resources. In a typical peer-to-peer

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network, each node has access to at least some of the resources on all other nodes.
A computer can act as both a server and a client. For example, a computer in the
network can have a shared printer connected to it; another computer can have
shared Internet connection connected; and another can have database software
that other computers can use. Many operating systems such as Windows 10,
Windows 8, Windows 7 and the Macintosh OS, have built-in features to support
peer-to-peer networking.

Peer to Peer Network Architecture

Client-Server Model Peer-to-peer Model
Advantages: Advantages:

Centralized control. Easy and simple to set
Good for centralized processing and up only requiring a hub
service. or a switch to connect all
Security is more advanced than a peer- computers together.
to-peer network You can access any file on
A client-server can be scaled up to the computer as long as it
many services that can also be used by is set to a shared folder
multiple users. If one computer fails
More reliable (dedicated server). to work all the other
computers connected to it
still continue to work
Less expensive

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Disadvantages: Disadvantages:
Needs a dedicated server Security is not good while
Expensive to buy and maintain setting passwords for files
When the server goes down or crashes that you do not want people
all the computers connected to it to access
become unavailable to use. It does not run efficiently if
you have many computers.
Not suggested if there
are more than 8 – 10
computers in a network
Less reliable

Network Topologies

The layout of the cables that connect the nodes (device attached to a network)
of the network is called network topology. Network designers consider several
factors while deciding which topology or combination of topologies to use: the type
of computers and cabling in place, the distance between computers, the speed at
which data must travel around the network, and the cost of setting up the network.
Here we discuss some major types of topologies used in Local Area Networks.

Bus Topology:

A bus topology network uses a segment of a single cable to connect nodes. All the
nodes and devices are connected in a series to the cable. Terminators are attached
at the cable’s start and endpoints.

BUS Topology

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Advantages

It uses the least amount of cabling of any topology.
Addition of new nodes to network is easy.
It is easy to set up computers and other devices through a single wire.

Disadvantages

The whole network system collapses if the shared communication line fails.
Terminators are necessary at both ends of the cable.
Difficult to detect fault in the network.

Star Topology:

In a star network topology, all nodes are connected to a central device called a
hub/switch. The star topology is probably the most common topology. Data packets
travel through the hub. They are sent to the attached nodes, eventually reaching
their destinations. Some hubs, known as intelligent hubs (switch), can monitor
traffic and help prevent collisions.

Desktop PC Printer

Laptop

Switch Desktop PC

Printer

Desktop PC Laptop

Desktop PC

Star Topology

Advantages

A broken connection between a node and the hub does not affect the rest of
the network.

Faults are easy to detect and it is easy to set up network devices.
No disruptions to the network while connecting or removing network devices.

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Disadvantages

The system crucially depends on central device (hub or switch). If it fails,
entire network fails.

It requires more cable length than a bus topology.
Expensive than bus topologies.

Ring Topology:

The ring topology connects the network’s nodes in a circular chain. The last node
connects to the first, completing the ring. Each node examines data as it travels
through the ring. If the data packet, known as a token, is not addressed to the
node, the node passes it to the next node. There is no danger of collisions because
only one packet of data travels in the ring at a time. If the ring is broken, however,
the entire network is unable to communicate.

Ring Topology

Ring Topology

Advantages

An orderly network where every device has access to the token and the
opportunity to transmit.

Supports optical fiber cable that is very high-speed data transmission media.

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Disadvantages

One malfunctioning workstation can throw away the entire network.
Moves, adds, and changes of devices can affect the entire network.

Protocols

To be able to communicate with each other, network devices need a common
language. The language network devices use is called a protocol. A network is
governed by a protocol, which is an agreed-upon format for transmitting data
between two devices. There are many different types of protocols available, and most
protocols are actually a suite of several protocols, each with a different function.
For example, one protocol allows data transfer between hosts and another can be
used to retrieve email from a mail server.
Protocols take the form of software or hardware that must be installed on every
computer on the network. Protocols are defined and implemented in different levels
– hardware, operating system, and application.
Hardware-level protocols are implemented in the hardware chips while
manufacturing the network hardware such as Network Adaptor, Hub, etc. Ethernet,
Arc net, and Token Ring are examples of hardware-level protocols.
The operating system level protocols decide the addressing scheme of the nodes in
the network and the security schemes. NetBIOS, IPX/SPX, TCP/IP are examples
of operating system-level protocols.
Application-level protocols define how user-related services are carried out in
the network such as sending and receiving e-mails, transferring files, accessing
web pages, etc. HTTP, FTP, SMTP, POP, etc. are examples of application-level
protocols.
Using their own methods, protocols break data down into small packets in
preparation for transportation. Linking devices pass these packets to the various
pieces of equipment, including other computers and printers that are attached to
the network. A packet is a data segment that includes a header, payload, and control
elements that are transmitted together. The receiving computer reconstructs the
packets into their original structure. A complete protocol contains a set of smaller
protocols to do different tasks at different levels to perform a requested operation
in the network. OSI (Open Systems Interconnection) reference model, TCP/IP are
examples of protocol sets.

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A single LAN may utilize more than one protocol. Some of the most common
protocols in use today include the following:

TCP/IP

Originally associated with UNIX hosts, TCP/IP (Transmission Control Protocol /
Internet Protocol) is the protocol of the internet. It is required on any computer
that must communicate across the Internet. TCP/IP is now the default networking
protocol of Windows clients and servers, and many other OS's. TCP/IP uses IP
address to refer to each node in the network. An IP address is a set of four octal
numbers each ranging from 0 to 255 separated by a dot (.). IP address can be
in the range 0.0.0.0 to 255.255.255.255. Examples of IP address are 192.168.1.1,
157.240.13.35, 172.217.27.46, etc.

Network Transmission Media

The network transmission media refers to the means used to link nodes of a network
together. There are different types of transmission media. They are twisted-pair
wire, coaxial cable, fiber optic cable and wireless media. In wireless networks,
the atmosphere itself acts at the medium because it carries the wireless signals
that nodes and servers use to communicate.

Guided (Wired) Media

Guided Transmission Media use “cabling” system that guides the data signals
along a specific path. The data signals are bound by the “cabling” system. Guided
Media is also known as Bound Media or Wire Based Media.
The three guided media commonly used for data transmission are twisted pair,
coaxial cable, and optical fiber.

Twisted pair cable

Twisted pair cable normally consists of four pairs of wires. The individual pairs
of wires are separately insulated in plastic and then twisted around each other.
The complete set is enclosed together in a layer of plastic, (telephone system uses
this type of wiring). Except for the plastic coating, nothing shields this type of wire
from outside interference; so, it is also called Unshielded Twisted Pair (UTP) wire.
Cabling systems are categorized in terms of the data rates that they can sustain
effectively. Examples of categories of UTP cables are Cat.5, Cat 5e, Cat6, etc. UTP
cabling in networks uses RJ-45 connector.

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Unshielded Twisted Pair (UTP) wire

Some twisted pair cables include metal shielding over each individual pair of
copper wires. This type of twisted pair cable is called Shielded Twisted Pair (STP)
cable. This type of shielding protects cable from external EMI (Electromagnetic
Interferences). A twisted-pair wire was one considered a low-bandwidth medium,
but networks based on twisted-pair wires now support transmission speeds up to
1 Gbps (Gigabit per second)

Shielded Twisted Pair (STP)

Co-axial Cable:

Coaxial cables are groups of specially wrapped and insulated wire lines capable
of transmitting data at high rates. Coaxial cabling is used primarily in 10Base2
(Thinnet) and 10Base5 (Thicknet) ethernet networks. Like the cabling used in cable
television systems, it has two conductors. One wire is at the center of the cable, and
the other is a wire mesh shield that surrounds the first wire, with an insulator
inbetween. Coaxial cables offer much higher bandwidths than UTP cables.

A
C

B
D

A: outer plastic sheath, B: copper screen, C: inner dielectric insulator, D: copper core

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BNC (Bayonet Neill-Concelman) T-connector

Fiber Optic Cable

A fiber-optic cable is a hair-thin thread of glass that transmits pulsating beams
of light rather than electric current. Fiber optic cable can carry data at more than
a billion bits per second. Because of improvement in transmission hardware,
fiber-optic transmission speeds has now approached 100 Gbps. Fiber-optic cable
is immune to the electromagnetic interference that is a problem for copper wire.
Fiber-optic cable is not only extremely fast and can carry an enormous number of
messages simultaneously, but it is a very secure transmission medium.
As shown in the figure, electrical to light wave converter MC (Media Converter) at
the sender side converts electrical signals into light signals. These light waves are
then transmitted over the optical fiber to the receiver's end. The light to electrical
wave converter (MC) at the receiver side detects the light waves and converts them
back to electric signals.

Media Converter SC and ST connector

Unguided (Wireless) Media

Unguided transmission media is a carrier of data signals that flow through the air
or by radiation in the form of electromagnetic wave. They are not guided or bound
to a channel to follow through. They are classified by the type of wave propagation.

Microwave Transmission

Microwave transmission is line of sight transmission. The transmitting station
must be invisible contact with the receiving station. This sets a limit on the distance

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between stations depending on Microwave Transmission
the local geography. Typically the
line of sight due to the Earth's
curvature is only 50 km to the
horizon! Repeater stations must
be placed; so, the data signal can
hop, skip and jump across the
country.
Microwaves operate at high
operating frequencies of 3 to 10
GHz. This allows them to carry
large quantities of data due to
their large bandwidth.

Advantages

a. They require no right of way acquisition among towers.
b. They can carry high quantities of information due to their high operating

frequencies.
c. Low-cost land purchase: each tower occupies only a small area.
d. High frequency/short wavelength signals require small antennae.

Disadvantages

a. Attenuation by solid objects: birds, rain, snow, and fog.
b. Reflected from flat surfaces like water and metal.
c. Diffracted (split) around solid objects.
d. Refracted by the atmosphere, thus causing beam to be projected away from

the receiver.

Radio Wave

Radio frequencies are in the range of 300 kHz to
10 GHz. We are seeing an emerging technology
called wireless LANs. Some use radio frequencies
to connect the workstations, while others use
infrared technology.

Radio Wave

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Some frequency spectrum operates

Name Frequency (Hertz) Examples
UHF - Ultra High Frequencies 300 MHz (Mega = UHF TV (Ch. 14-83)
106)
VHF - Very High Frequencies 30 MHz FM & TV (Ch2 - 13)
HF - High Frequencies 3 MHz2 Short Wave Radio
MF - Medium Frequencies 300 kHz (kilo = 103) AM Radio
LF - Low Frequencies 30 kHz Navigation
VLF - Very Low Frequencies 3 kHz Submarine
Communications
VF - Voice Frequencies 300 Hz Audio

Satellite Communication

Satellites are transponders (units that receive on one frequency and retransmit
on another) that are set in geostationary orbits directly over the equator. These
geostationary orbits are 36,000 km from the surface of the Earth. At this point, the
gravitational pull of the Earth and the centrifugal force of rotation of the Earth are
balanced and they cancel each other out. Centrifugal force is the rotational force
placed on the satellite that wants to fling it out into space.

Satellite Communication

The uplink is the transmission of data to the satellite. The downlink is the
receiving data by the Earth station. Uplinks and downlinks are done by Earth
stations because they are located on the Earth.

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Bluetooth

Bluetooth is an open wireless protocol for
exchanging data over short distances from fixed
and mobile devices. Bluetooth provides a way
to connect and exchange information between
devices such as mobile phones, telephones, laptops,
personal computers, printers, Global Positioning
System (GPS) receivers, digital cameras, and Bluetooth

video game consoles through a secure, globally unlicensed Industrial, Scientific
and Medical (ISM) 2.4 GHz short-range radio frequency bandwidth. The Bluetooth
specifications are developed and licensed by the Bluetooth Special Interest Group
(SIG). Bluetooth is a standard and communication protocol primarily designed for
low power consumption, with a short-range (1 meter, 10 meters or 100 meters).

Network Operating System

We are already aware that computer needs an Operating System to manage its
resources and processes. When computers are connected in a network then the
Operating System needs to have additional features which enable it to communicate
with other computers in the network. When a computer is connected to a network,
the vulnerability of exposure of private data and information also increases. So,
the Operating System used must be able to handle the security issues of the
networked environment. The Operating System which can manage the computers
in a network is called the Network Operating System (NOS). There are different
Operating Systems suitable for managing networks. Different types of NOS are
used for different types of networks.

For example, all modern desktop operating systems, such as Macintosh OSX,
Linux, and Windows can function as peer-to-peer network operating systems.
UNIX/Linux and the Microsoft family of Windows Servers are examples of client/
server network operating systems. Network Operating Systems are equipped with
required protocols, security modules, and administrator's tools for managing the
network.

Network Administrator

Network Administrator is an individual or group of individuals responsible for
managing a company’s network infrastructure. Some of the jobs in this field include
designing and implementing networks, setting up and managing user accounts,
allowing and revoking rights to the users, installing and updating network software
and applications, and taking backup of the data in the server(s).

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Network Hardware

As data move among PCs, it needs to be channelled properly to reach its final
destination. To make this possible, the proper hardware must be attached to and
among all PCs.

Network Interface Card (NICs) Network Interface Card

A Network Interface Card (NIC), typically an expansion
card in a computer, is used to connect to the physical
network media. Some motherboards and most portable
computers are equipped with a built-in (onboard)
NIC. NICs are available for different types of network
media, the most common today being Ethernet NICs
with a RJ-45 socket for UTP/STP cabling.

In the case of a wireless NIC, there is no port: it may or may not have an antenna.
There might be a led light which indicates that wireless card is activated.

Network cards

Wireless Adapter

A PC or laptop needs a wireless adapter card (wireless NIC) that meets 802.11b
or 802.11g standards to connect another wireless device or wireless router. This
card uses an antenna to communicate through microwaves.

Wireless Adapter

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Hub

A hub is a connection point for different types of devices on a network. This is not a
particularly fast connection because it broadcasts the packets it receives to all nodes
attached to its ports. There are two main types of hubs: passive hubs and active
hubs. An active hub takes the incoming frames, amplifies the signal, and forwards
it to all other ports, while a passive hub simply splits the signal and forwards it.

Active Hub / Switch Passive hub

Bridge

A network bridge joins two separate computer networks to
enable communication between them, and allows them to work
as a single network. These networks might be the same type
of network like two Ethernet networks, or different networks
like an Ethernet network and HomePNA network. Bridge
translates the data packets transmitted over the network so
Bridge

that another network can use it. For example, a bridge connects
two networks in which one network uses fiber-optic communication medium and
the other uses coaxial cable, or one of which uses Ethernet technology and the
other uses Token Ring technology. A bridge looks at the information in each packet
header and forwards data travelling from one LAN to another.

Bridge Network

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Switch

A switch is a device in a computer network that connects together other devices.
Multiple data cables are plugged into a switch to enable communication between
different networked devices. They also keep a table with MAC addresses per port to
make switching decisions, similar to bridges. The main difference is that a switch
has more ports than a bridge, and instead of interconnecting networks it is typically
used to connect hosts and servers like a hub does, but offers dedicated bandwidth
per port. Hence, it offers much higher network performance than hubs. Modern
switches can even function as routers allowing multiple LANs to be interconnected
by linking each LAN’s switches together. This is called an uplink.

Switch Switch Rack

Router

Routers are used to interconnect multiple networks and
route information among these networks by choosing
an optimal path ("route") to the destination based on
addressing information from protocols such as TCP/
IP or IPX/SPX. A router looks at each packet’s header
to determine where the packet should go. Then, it
determines the best route for the packet to take toward
its destination. It is connected to at least two networks,
commonly two LANs or WANs or a LAN and its ISP’s
network. Routers are located at gateways - the places
where two or more networks connect. Routers provide Router

a security element as well. They can include several forms of firewall security.
One form of protection comes from the NAT (Network Address Translation) table,
which hides the company’s internal node IP addresses from the internet.

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Repeater

Repeaters are used to extend the maximum distance in a network segment.
Repeaters grab the incoming electrical signal from the media, amplify it, and send
it out. Repeaters can be used to extend the segment of wired connection or repeater
towers are used to forward amplified microwave signals to the next tower.

Repeaters Gateway

Gateway

Gateway is used to connect among different types of networks
in which you need a gateway, placed at a junction (gateway)
between two or more networks with dissimilar technologies.
For example, a TCP/IP network and IPX/SPX network can be
connected using a gateway. A gateway is a node on a network
that serves as an entrance/exit to another network. In the
small business or home network, the gateway is the device that
routes data from a local PC to an outside network such as the
internet.

Gateway Networking

Wireless Technology

Wireless communication technology is a modern alternative to traditional wired
networking that relies on cables to connect digital devices together. Wireless

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technologies are widely used in both home and business computer networks.
Wireless Access Points (WAPs or APs) are specially configured nodes on Wireless
Local Area networks (WLANs). Access points act as a central transmitter and
receiver of WLAN radio signals.

phone

cordless

GSM smartphone
tablet
AP

smartwatch Router

laptop Alexa

Access Point and wireless devices

Internet and its Services

The internet is a network of networks – a global communications system that
links together thousands of individual networks. As a result, virtually any computer
on any network can communicate with any other computer on any other network.
These connections allow users to exchange messages, to communicate in real-time
(seeing messages and responded immediately) to share data and programs, and
to access limitless stores of information. The internet uses TCP/IP protocol for
communication among computers.

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The internet has become so important that its use is considered as an essential part
of computer use. Most companies and organizations do their business with many
other companies and organizations. For this reason, they need to have systems
those are flexible enough to handle ever-changing array of partners or customers.
An effective way to do this is to create corporate networks that look and function
like the internet, and these networks grant access to authorized external users
through the internet. These specialized business networks are called intranets
and extranets.
An intranet is a corporate network that uses the same protocols as the internet,
but which belongs exclusively to a corporation, school, or some other organization.
The intranet is accessible only to the organization's employees. If the intranet is
connected to the Internet, then it is secured by a special device called a firewall,
which prevents unauthorized external users from gaining access to it.
An extranet is an intranet that can be accessed by authorized outside users over
the internet. To gain entrance to the extranet, the users must log on to the network
by providing a username and password.

Brief History of the Internet

J.C.R. Licklider of MIT first proposed a global network of computers in 1962 and
moved over to the Defense Advanced Research Projects Agency (DARPA) in late
1962. Roberts moved over to DARPA in 1966 and developed his plan for ARPANET.
Then the seeds of the internet were planted in 1969 when the Advanced Research
Projects Agency (ARPA) of the U.S. Department of Defense began connecting
computers at different universities and defence contractors. The Resulting
networking was called ARPANET. The internet evolved from basic ideas of
ARPANET for interconnecting computers and was used by research organizations
and universities initially to share and exchange information.
In the mid-1980, another federal agency, the National Science Foundation (NSF)
joined the project after the Defense Department stopped funding the network,
NSF established five “supercomputing centers” that were available to anyone
who wanted to use them for academic research purposes. The NSF expected the
supercomputer’s users to use ARPANET to obtain access, but the agency quickly
discovered that the existing network could not handle the load. In response, the
NSF created a new, higher-capacity network, called NSFnet, to complement the
older, overloaded by then, ARPANET. The link between ARPANET, NSFnet, and
other networks was called the Internet.

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The original ARPANET was shut down in 1990, and government funding for
NSFnet was discontinued in 1995. However, the commercial internet backbone
services replaced them. By the early 1990s, interest in the internet began to
expand dramatically. Since then, the internet has grown rapidly to become the
world's largest network. Today, the internet connects thousands of networks
and hundreds of millions of users around the world. It is a huge, cooperative
community with no central ownership. This lack of ownership is an important
feature of the Internet because it means that no single person or group controls the
network. Although there are several organizations (such as The Internet Society
and the World Wide Web Consortium) that propose standards for internet-related
technologies and guidelines for its appropriate use.

Main Services of the Internet

The Internet acts as a carrier for several different services, each with its own
distinct features and purposes. The most commonly used internet services are:

The World Wide Web File Transfer Protocol
Telnet Internet Relay Chat
E-commerce Electronic mail

The World Wide Web (WWW)

The World Wide Web (also called Web in short)
was created in 1989 at the European Particle
Physics Laboratory in Geneva, Switzerland. The
World Wide Web is a term used to describe the
interlinked collection of hypertext documents and
multimedia content available on the internet.
You use a Web browser to search, find, view, and
download information on the internet. Over the last few years, the Web has become
one of the most popular Inter services.

The Web is a collection of internet host systems that make these services available
on the internet using the HTTP (Hypertext Transfer Protocol). Web-based
information is usually delivered in the form of hypertext and hypermedia using
HTML.

Many people believe that the Web and the internet are the same things. In fact, they
are two different things. The web is a service (a system for accessing documents)
that is supported by the internet (a gigantic network).

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File Transfer Protocol

File Transfer Protocol (FTP), a standard internet protocol, is the simplest way to
exchange files between computers on the Internet. Like the Hypertext Transfer
Protocol (HTTP), which transfers displayable Web pages and related files, and
the Simple Mail Transfer Protocol (SMTP), which transfers e-mail, FTP is an
application protocol that uses the internet's TCP/IP protocol. Web developers use
FTP to upload the website to the Web server in the internet so that other users
can access the website. It is also commonly used to download programs and other
files to user's computer from the internet servers.

As a user, you can use FTP with a simple command-line interface (for example,
from the Windows MS-DOS Prompt) or with a FTP client program (e.g. Cute FTP,
WS_FTP Pro, Filezilla) that offers a graphical user interface. Your Web browser
can also make FTP requests to download programs you select from a Web page.
Using FTP client, you can also update (delete, rename, move, and copy) files in
a server. You need to log on to an FTP server. However, publicly available files are
easily accessed using anonymous FTP archives.

Telnet

Telnet is one of the simplest tools or facility of the internet that allows user to
use a remote computer (far distance computer) through internet. When you are
connected to a remote host via Telnet, you interact with that computer and operating
system and issue commands as if you were directly connected to the computer.
When the Telnet program connects your computer to the remote computer, the
remote computer usually asks you to enter a username and password.

Internet Relay Chat (IRC) and Web-Based Chat Online communication

Internet relay chat or just chat room is a web
application that allows two or more people to
communicate by typing messages to each other
at the real-time. Real-time communication
means communicating with another user in the
immediate present. There are many types of chat
rooms used on the internet.

Use of a chat room

Chat is fun and instantaneous
Great for formal and informal meetings

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Communicate with experts, authors, scientists, business community, etc.
Share ideas quickly regardless of distance
Brainstorming between peers, students, and colleagues
Collaboration on projects or rich tasks
Cultural experiences
Social experience
Quieter students can communicate easily
People can enjoy the anonymity of chat

E-commerce

E-Commerce is also one of the important services
of internet through which you can sell or buy
goods. In simple terms, it is doing business
through the internet or online. What can you
buy online? You can buy everything from cars
to appliances, electronics to jewellery, clothes to
books, fine wines to old-fashioned candies. You
can use the e-commerce service of the internet
through some special web sites. Some e-commerce
E-commerce

sites are: kaymu.com.np, muncha.com.np, ebay.
com, amazon.com, alibaba.com, flipkart.com, meroshopping.com, sajhapasal.com,
etc.

E-mail

Electronic mail service (e-mail) enables an internet user to send a message to
another internet user in any part of the world. E-mail is one of the first services of
the internet. An e-mail message takes a few seconds to several minutes to reach
its destination because it travels from one network to another until it reaches its
destination.

Email service has many similarities with the postal mail service. All internet users
have an e-mail address, just as all of us have a postal address. Each internet user
has a mailbox in a mail server. When sending email to another user, a sender
specifies the e-mail address of the receiver, just as we write the postal address of
the receiver of a post in postal mail system. E-mail service delivers the sent mail
into its receiver’s mailbox. The receiver extracts the mail from his/her mailbox
and reads it at his/her own convenient time, just as in a postal mail system. After

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reading the message, the receiver can save it, pass it to someone else, or respond
by sending another message back.

Message in e-mail service can contain not only text documents but also image,
audio, and video data as an attached file. With e-mail service, the internet has
proved to be a rapid and productive communication tool for millions of users. As
compared to paper mail, telephone, and fax, many prefer e-mail because of the
following advantages:

It is faster and cheaper.
The persons communicating need not be available at the same time.
E-mail documents can be stored in a computer.
It ensures a much higher degree of security. Only an authorized person can

open the mail.
It is more reliable.
Same e-mail can be sent to a different person.
It can be accessed from any part of the world.
We can send any form of data like text, pictures, audio, or video along with

mails as an attachment.

Gmail

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Video Conferencing Video Conferencing

In video-conferencing technology, two or more
people at different locations can see and hear
each other at the same time, sometimes even
sharing computer applications for collaboration.
Video-conferencing offers possibilities for schools,
colleges, and libraries to use these systems for a
variety of purposes, including formal instruction
(courses, lessons, and tutoring), connection
with guest speakers and experts, multi-school
project collaboration, professional activities, and
community events.

Placing a video call is a lot like placing a telephone call. After you connect, you see
the other person in color video on a TV screen and may be able to transfer files
or collaborate via options such as document sharing or white-boarding. A video-
conferencing system requires the audiovisual equipment, which includes a monitor,
camera, microphone, and speaker, and a means of transmission. Rather than an
internet-based connection, such as that used by web cams, which have to share
bandwidth with other internet data, a compressed video system on a dedicated
bandwidth provides smooth audio and video.

Video conferencing

Search Engines / Directory Services

Most people are primarily interested in tools for finding information on the World
Wide Web. Originally, there were two kinds of search services on the Web: Engines
and Directories.

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Search engines should be your first choice when you know exactly what
you are looking for. They also cover a much larger part of the Web than the
directories. Search engines are "engines" or "robots" that crawl across the
Web looking for new web pages. These robots read the web pages and put the
text (or parts of the text) into a large database or index that you may access.
None of them covers the whole Net, but some of them are quite large. The
major players in this field are Google, Bing, Yahoo Search (which is not
the same as the Yahoo! Directory), Ask.com, AOL.com, Baidu are some
popular search engines.

Search directories are hierarchical databases with references to websites.
A directory enables you to search for information by selecting categories of the
subject matter. The directory separates subjects into general categories (such
as “companies”), which are broken into increasingly specific subcategories.
After you select a category or subcategory, the directory displays a list of Web
sites that provide content related to that subject. Look for directory at http://
www.looksmart.com

Downloading / Uploading

Downloading is the transmission of a file from
one computer system to another, usually smaller
computer system. From the Internet user's point-of-
view, to download a file is to request it from another
computer (or from a Web page on another computer)
and to receive it. Where uploading is transmission
in the other direction: from one, usually smaller
computer to another computer. From an internet
user's point-of-view, uploading is sending a file to
a computer that is set up to receive it. People who share images with others on
bulletin board systems (BBS) upload files to the BBS.

Blog

A blog (a contraction of the term web log) is a type of website, usually maintained
by an individual with regular entries of commentary, descriptions of events, or
other material such as graphics or video. Entries are commonly displayed in
reverse-chronological order. "Blog" can also be used as a verb, meaning to maintain
or add content to a blog.

Many blogs provide commentary or news on a particular subject; others function
as more personal online diaries. A typical blog combines text, images, and links to
other blogs, Web pages, and other media related to its topic. The ability for readers

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to leave comments in an interactive format is an important part of many blogs. Most
blogs are primarily textual, although some focus on art, photographs (photoblog),
sketches (sketchblog), videos (vlog), music (MP3 blog), audio (podcasting), which
are part of a wider network of social media. Micro-blogging is another type of
blogging, one which consists of blogs with very short posts. Some of the popular
blogs are http://www.travelpod.com, http://googleblog.blogspot.com, http://www.
weblognepal.com/. You can create your own blog if you have a google account which
is available in more options.

Blogging Online Banking

Online Banking

The term online banking refers to
using a bank’s web site to handle
banking –related tasks. Individuals
and business alike can visit any
bank’s Web site and do the following:

Create an account
Transfer funds
Record or view transactions /

statement
Reconcile statements
Pay bills of school, electricity,

cellphone, etc.

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Social Media Different kinds of social media

Social media are online platforms
that help to connect people together
from far and near. It is used to build
a relationship among people. It has
been observed that social media
have a wider and faster means of
circulating information not only to
the students of an institution but
also to the generality of the public.
Social media platforms include
Facebook, WhatsApp, Google
Plus, Blogs, Twitter, Instagram,
YouTube and much more.

POINTS TO REMEMBER

The process of sending and receiving data and information between two or more
than two people is known as communication.
Simplex mode is the transmission of data or information can take place in only one
direction.
Twisted pair wire is made up of copper and a pair of wires are twisted together and
insulated with plastic.
Co-axial cable is made up of copper or aluminium wire with an inner conductor
surrounded by insulating layer and again surrounded by conducting shield.
Fiber optic cable uses light wave to carry data signal from one end of the cable to
other end.
Nowadays, wireless technology is used in communication technology and uses a
radio signal for receiving and transmitting electronic data.
In Nepal, radio wave transmission is used in rural and hilly areas.
Microwave is high-frequency wave which used to transfer signals through
atmosphere.

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Text, photo, video, etc. can be transfer worldwide by using satellite communication.
The computer network is two or more than two computers connected to each other
through wired or wireless media to share data or information, hardware, software and
other resources.
The hardware used in network are computer set, modem, hub, NIC card, bridge,
repeater, etc.
NIC card provides a port on the back of system unit to connect a computer in network.
The different types of connectors are RJ- 45 connector, BNC connector and ST
connector.
Network software is important software which controls and manage computer
network.
A set of rules followed for interconnection and communication between computers in
a network is called protocol.
The main three types of computer network are LAN (Local Area Network), MAN
(Metropolitan Area Network) and WAN (Wide Area Network).
Network architecture defines how the computer communicates and interacts with
each other on network.
Network topology is the inter-connected pattern of network components.
The worldwide collection of computer networks and that use TCP/IP protocols to
communicate with one another using wire or wireless media as well as network
devices is called internet.
E-mail is sending and receiving messages electronically through the internet. 
The search engine is the communication program that searches documents for
specified keywords and returns a list of the documents where the keywords were
found.
E-commerce means buying and selling of goods, products, or services over the
internet.
Social media are online technology platforms that help to connect people together
far and near.

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xercise

1. Answer the following questions:

a) What is computer network. List its importance.

b) Write any four advantages and disadvantages of computer network.

c) Differentiate among simplex, half-duplex, and full-duplex modes of data transmission.

d) What are modems? What purpose do they serve in data communication systems?

e) Define LAN with its main objectives.

f) Differentiate between a LAN and WAN. Write an example of each.

g) Differentiate between peer-to-peer and Client-server network architectures.

h) List four types of network topologies with diagram used in wire-based networks.

i) What are the protocols? Write the name of some common network protocols.

j) Define transmission media. Explain the types of transmission media in short with one
example each.

k) What is NOS? Give some examples.

l) Differentiate between guided and unguided transmission media.

m) Explain the terms “bandwidth”.

n) What is fiber optic cable?

o) Why do signals travel faster in fiber optics?

p) Explain how microwave systems are used for communication between two distant
stations.

q) What is a repeater?

r) Write short notes on:

i. Modem ii. Switch iii. Bridge iv. Router

v. Gateway vi. Wireless technology

s) Define internet with any four services of it.

t) What is an e-mail? Explain.

u) What is file transfer protocol? Why it is used?

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v) List four things you can do with an e-mail message, once you receive it.
w) What is a search engine? Name some popular search engines.
x) What is video conferencing?
y) What is e-commerce? List any four e-commerce sites.

2. Fill in the blanks.
i. In simplex communication the message is transmitted in only one .....................
ii. In Half Duplex communication the message can be transmitted in both ways
but .....................
iii. Transmitting message over a distance using wired or wireless media is called ..................
iv. Digital signals have two amplitude levels called .....................
v. Telephone lines carry .....................signals.
vi. .....................is the technique of converting a digital signal to analog form.
vii. A computer uses ..................... signal that consists of ON / OFF pulses.
viii. A modem’s transmission speed is measure in .....................
ix. Bandwidth is measured in .....................
x. ..................... is the type of network which covers relatively larger geographical area.
xi. One popular type of server-based network is the .....................
xii. In a star network, all nodes are connected to a central device called a .....................
xiii. A centralized computer that allows multiple remote users to share the same printing
device is referred to as a .....................
xiv. The language network devices use is called a .....................
xv. ..................... transmission Media use “cabling” system that guides the data signals
along a specific path.
xvi. Twisted pair cable normally consists of .....................pairs of wires
xvii. .....................cables offer much higher bandwidths than UTP cables.
xviii. A(n) ..................... is a thin strand of glass that transmits pulsating beams of light at
speed that approach 100 Gbps.
xix. Optical fiber is a ..................... transmission media.
xx. ..................... transmission media is carrier of data signals that flow through the air or
by radiation in the form of electromagnetic wave.
xxi. Repeaters are used to ..................... the maximum distance a network segment

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xxii. Gateway is used to connect between .....................types of networks.

xxiii. The Internet uses ..................... Protocol

xxiv. Mozilla Firefox, Google Chrome, Safari, Opera, Internet Explorer, Maxthon, SeaMonkey
are some of the most popular .....................

xxv. Online shopping means ..................... or ..................... through a web site.

3. Give appropriate technical terms of the followings.

i) Data transmission in one direction only that is to send or receive only.
ii) A network limited to a room or building.
iii) A main computer in the computer Network.
iv) Each computer or device in a network.
v) Cabling structure of LAN.
vi) A physical layout of network through which network devices are connected.
vii) The rules that makes network communication.
viii) A device that connects dissimilar networks.
ix) A cable that transmits light signals rather than other transmission.
x) Type of network architecture that doesn't specify a server and workstation.
xi) A type of topology in which each node is connected to two other adjacent nodes forming

a loop.
xii) An operating system that can handle the network.
xiii) Device which boosts the strength of the received signal and retransmits it.
xiv) A business through Internet.
xv) The process of transferring data/file from the user’s computer to the Internet.
xvi) Software used to open Webpages.
xvii) Visual communication over the internet.

4. Give full forms of the following abbreviations:

i. bps ii. Kbps iii. GSM iv. Mbps

v. Modem vi. ADSL vii. LAN viii. WAN

ix. WAP x. WLAN xi. IBM xii. CAN

xiii. TCP/IP xiv. HTTP xv. FTP xvi. SMTP

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xvii. POP xviii. UTP xix. STP xx. EMI
xxi. UHF xxii. VHF xxiii. GPS xxiv. NOS
xxv. NIC xxvi. MAC xxvii. DARPA xxviii. ARPA
xxix. ADSL xxx. DSL xxxi. FTP xxxii. SMTP
xxxiii. E-mail xxxiv. ISP xxxv. POP xxxvi. TCP/IP
xxxvii. HTTP xxxviii. NAT

Activities

1. Draw the “Types of a computer network” on chart paper and paste in your class room.

2. Complete the following exercises as directed by your instructor. (Note: This exercise
assumes you are using Windows XP/ 7/ 10 or Windows 2000)

A. Explore your network.
i. On your Windows desktop, double-click on the My Network Places icon. The My
Network Places window opens. This window lets you access all the computer,
folders, files, and devices on the network.
ii. Find the icon named Entire Network and double-click on it. What do you see?
Because every network is unique, the contents of this window vary from network
to network.
iii. Following your instructor’s directions, click on icons and open new windows to
explore your network. How many network resources can you access?
iv. When you finish exploring, close all open windows.

B. Go to the command line prompt typing command at start>run
Now type there ipconfig/all and note down your computer IP address and Physical
(MAC) address.

C. Open Google.com in a web browser and type my ip, press on enter and note it
down. This is your public IP assigned by your ISP to connect to the internet.

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3. Make a PowerPoint presentation on topic:

“How do internet and its services help us to develop better society?”

Project Idea

Choose one service that internet has been providing to us or you can imagine (develop)
a new idea which is possible through internet. Limit yourself with only one
service/idea and present it in depth with all the required specificity. Your presentation
may include multimedia files, pictures, cartoons, graphs, bar charts, etc. Your
presentation may include information in the following order:

i. Introduction

(Define/introduce that idea/history of idea/summary of things you are going to
present in this presentation)

ii. Main Body

(Its use/ beneficial aspects or target group/how it works, argumentation about
do’s and don’ts, relate human development in socio-economic prospects,
benefits and limitations with examples)

iii. Conclusion

(Conclude your argumentation with logical interpretation and integrate it with
human development.)

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Unit Ethical and Social

1.2 Issues in ICT

Introduction

In simple terms, ethics refers to a set of principles that guides our behaviour to
be fair, honest, and transparent. Ethics are the principles of right and wrong. It
is derived from the Greek word “ethos” which refers to character, guiding beliefs,
standards, or ideals that pervade (comes across) a group, community, or people.

Illegal Cyber Activity

The technology revolution of the twentieth century starting with the widespread
use of the internet and home computers has a new set of ethical and social concerns
that people a hundred years ago could not have imagined, for example, how
personal information and online privacy should be protected. Who gets to own the
information about our habits and “likes”? Before the start of the internet, people
thought about and controlled their personal information in very different ways.
Today, many of us lead complex online lives, and we may not even realize how
our personal information is being collected and used. Many online companies can
collect data on the purchasing patterns, personal preferences, and professional/
social affiliations of their customers without their even knowing about it.

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There are so many social networking sites most of the people are connected to at
least one such sites, but we do not know exactly whether our personal information is
properly maintained. It has created a lot of issues which has encouraged our digital
society to focus on the ethics relating to ICT.

Computer Ethics

Computer ethics is a set of moral principles Computer hacking
or code of conducts that regulates the use of
computers systematically without making
harm to other users. It gives awareness to
the user regarding the immoral behavior and
activities in the computing field.

Some important commandments of computer ethics are:

You should not use a computer to do any harm to other people.
You should not publish fake information using a computer and social network.
You should not snoop around in other people’s computer and their files.
You should not destroy or delete the records of other people.
You should not steal someone's private data.
You should not copy software and any other digital material for which you

have not paid.
You should not use other people's computer resources without authorization.
You should think about the social consequences of the program you write or

content you share.

Cyber Ethics

Cyber ethics is a code of safe and responsible
behavior for using the internet. Just as we are
taught to act responsibly in everyday life with
lessons such as "Don't take what doesn't belong
to you" and "Do not harm others," we must act
responsibly in the cyber world as well.

Cyber ethics is distinct from cyber law. Laws are Cyber crime
formal written directives that apply to everyone,
interpreted by the judicial system, and enforced

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by the police. The objective of cyber ethics is to ESTABLISHING A CULTURE OF
PROPER USE of the internet and computers.

DO DON’T

You can use the internet to take help Don't copy information from the
for your school work. internet and call it your own.

You can learn about music, video Don't use the internet to download or
and games using the internet . share copyrighted material.

You can use the internet to Don't use the internet to communicate
communicate with friends and with strangers.
family.
Don't pretend to be someone else.

Don't be rude or use bad language.

Don't give anyone personal information
or passwords.

Don’t break into someone else’s
computer.

Don’t use someone else’s password

Don’t cyberbully.

Cyber ethics mainly deals with the following domains:

Privacy Intellectual Property Rights Security

Accuracy Accessibility Censorship and Filtering

Ethical Hacking Ethical Hacking

Along with the above commandments
of computer ethics, the unauthorized
uses of computer or internet resources
is called hacking. Hacking is generally
considered as a criminal activity and the
individuals who are engaged in hacking
are called hackers. But to safeguard
such hacking activities a person is
hired by a company or individual who

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attempts to bypass system security and search for any weak points that could be
exploited by malicious hackers. This information is used by the individuals or the
organizations to improve system security. Those authorized persons are called
Ethical hackers and their activity is called Ethical Hacking. Testing system for
any security-related vulnerabilities is called Vulnerability and Penetration Testing
(VAPT).

Digital Citizenship

As most of the people in the present world are already associated with the present
digital world connect through internet, computer, tablet, smart phone, etc. The
concept of digital citizenship has become very important.

Citizenship is defined as one's belongingness towards the community where he/
she belongs to, along with the rights, responsibilities and privileges of being a
citizen. Digital citizenship generally focuses on digital community. Each member
needs self-awareness and self-monitoring attitude while communicating with other
members of the community she is connected with and follow the guidelines that
govern ethical and responsible use of technology.

A global citizen can be a learner, a leader, or a creator of the community. She
has to be social and stay digital round the clock. Technology plays a critical role
in her lives. She lives and thrives in both offline as well as an online community
which have different cultures and she has to follow them actively. Since digital
communities are growing at a phenomenal rate, policies and programs are
developed for the safety of community members. She sees the entire world as a
community in which people live and prosper together without the geographical
barrier. Following are the elements of digital citizenship:

i. Digital Access: The state of full electronic participation in society
ii. Digital Commerce: The act of promoting the purchase of goods through

electronic means
iii. Digital Communication: Electronic exchange of information
iv. Digital Literacy: Teaching and learning about teaching and technology
v. Digital Security: Electronic precautions
vi. Digital Health: The solution to health problems using digital technology
vii. Digital Law: Act, rules, and regulations required for performing electrical

work

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