basic computer communication network -lesson note

JSS 2 DIGITAL TECHNOLOGIES

Basic Computer Communication Networks

CLASS: JSS 2 (Basic 8)

TERM: First Term

WEEK: 2

TOPIC: Basic Computer Communication Networks

DURATION: 80 Minutes (Double Period)

SUBTOPICS

• Meaning of computer communication networks
• Need for computer networks
• Local Area Network (LAN)
• Metropolitan Area Network (MAN)
• Wide Area Network (WAN)

BEHAVIOURAL OBJECTIVES

By the end of the lesson, students should be able to:

• Define a computer network.
• Explain why computers and digital devices are connected in networks.
• State reasons for using computer networks.
• Define LAN, MAN and WAN.
• Differentiate between LAN, MAN and WAN.
• Give examples of where different network types may be used.

INTRODUCTION

Imagine a computer laboratory containing twenty computers. If every computer worked completely on its own, students might not be able to share files, use the same printer or communicate easily with another computer.

When computers and other digital devices are connected together, they can communicate and share information and resources. This arrangement is called a computer network.

Computer networks are used in schools, offices, homes, banks, businesses, hospitals and many other organisations.

MEANING OF COMPUTER NETWORK

Definition: A computer network is a group of two or more computers or digital devices connected together so that they can communicate and share information or resources.

A network may connect computers using physical cables or wireless communication. The devices connected to a network can include computers, printers, smartphones, servers, routers and other network equipment.

Examples of Things Shared on a Network

• Files and documents
• Printers
• Internet connections
• Applications and other resources
• Information and messages

WHY DO WE NEED COMPUTER NETWORKS?

Computer networks make it possible for connected devices and users to communicate and share resources more easily.

1. Sharing Files

Users on a network can share documents, pictures and other files without necessarily transferring them using physical storage devices.

2. Sharing Hardware

Several computers can share devices such as printers and scanners. This can reduce the need for every computer to have its own printer.

3. Sharing Internet Connections

A network can allow several devices to access the Internet through a shared connection.

4. Communication

Networks allow users and devices to communicate by sending messages, files and other information.

5. Collaboration

People working in the same organisation can use networks to work together and access shared information.

TYPES OF COMPUTER NETWORKS

Computer networks can be classified in different ways. One common classification is based on the geographical area covered by the network.

The three network types introduced in this lesson are:

• LAN – Local Area Network
• MAN – Metropolitan Area Network
• WAN – Wide Area Network

LOCAL AREA NETWORK (LAN)

LAN means Local Area Network. It is a network that normally connects computers and devices within a small geographical area.

A LAN may be found in a classroom, computer laboratory, office, school building or home.

Examples of LAN

• A school computer laboratory network
• A network within an office building
• A home network connecting computers and other devices

Features of LAN

• It covers a relatively small area.
• It can provide fast communication between connected devices.
• It can allow resources such as printers to be shared.
• It may use cables, wireless connections or both.

METROPOLITAN AREA NETWORK (MAN)

MAN means Metropolitan Area Network. It is a network designed to connect computers or smaller networks across a larger geographical area such as a city or metropolitan area.

A MAN can connect networks located in different buildings or locations within a city or metropolitan region.

Example

A large organisation with offices in different parts of the same city could use a metropolitan-scale network to connect those locations.

WIDE AREA NETWORK (WAN)

WAN means Wide Area Network. It is a network that covers a large geographical area and can connect devices or networks across cities, countries or continents.

WANs are useful when organisations need to connect locations that are far apart.

The Internet is the most widely known example of a global network made up of interconnected networks.

LAN, MAN AND WAN COMPARISON

Network	Meaning	Typical Coverage	Example
LAN	Local Area Network	Small area such as a room, building or school	School computer laboratory
MAN	Metropolitan Area Network	City or metropolitan area	Networks connecting offices across a city
WAN	Wide Area Network	Large geographical area such as countries or continents	Networks connecting offices in different countries

WIRED AND WIRELESS NETWORKS

Wired Network

A wired network uses physical cables to connect devices. Examples of network cables include Ethernet cables.

Wireless Network

A wireless network allows devices to communicate without a physical network cable between them. Wi-Fi is a common example of wireless network communication.

Wired Network	Wireless Network
Uses physical cables.	Uses wireless communication signals.
Devices are physically connected through network media.	Devices can connect without a network cable.
Commonly uses Ethernet cables.	Commonly uses Wi-Fi or other wireless technologies.

ADVANTAGES OF COMPUTER NETWORKS

• They make resource sharing possible.
• They support communication between users and devices.
• They make file sharing easier.
• They can allow multiple users to share an Internet connection.
• They support teamwork and collaboration.
• They can make management of shared resources easier.

DISADVANTAGES / CHALLENGES OF NETWORKS

• Network equipment can be expensive to install and maintain.
• A network can be affected by technical faults.
• Poor security can expose shared information to unauthorised users.
• Malware can spread between connected devices.
• A network may require trained personnel to manage it properly.

CLASS ACTIVITY

Divide the class into small groups. Ask each group to identify examples of computer networks they have seen at home, school or in their community.

Each group should then answer:

1. What devices are connected?
2. What is being shared?
3. Is the network likely to be a LAN, MAN or WAN?
4. Is it wired, wireless or a combination?

SUMMARY

A computer network is a group of connected computers or digital devices that communicate and share information or resources. Networks are useful for file sharing, hardware sharing, communication, Internet access and collaboration.

LAN, MAN and WAN are commonly classified according to the geographical area they cover. LAN normally covers a small area, MAN can cover a city or metropolitan area, while WAN covers a much larger area. Networks can also use wired or wireless communication.

EVALUATION QUESTIONS

1. What is a computer network?
2. State four reasons why computer networks are needed.
3. What does LAN stand for?
4. What does MAN stand for?
5. What does WAN stand for?
6. State one difference between LAN and WAN.
7. Give one example of where a LAN can be used.
8. What is the difference between a wired and wireless network?

ASSIGNMENT

Draw a simple diagram of a LAN connecting three computers, a printer and a network device. Label the devices and write three benefits of the network.

QUICK PRACTICE QUIZ

1. What is a computer network?

A. A group of connected devices that can communicate and share resources B. A single computer without connections C. A type of printer D. A computer game

2. Which network normally covers a small area such as a school computer laboratory?

A. WAN B. MAN C. LAN D. Global network

3. What does WAN stand for?

A. Wireless Access Network B. Wide Area Network C. Web Access Node D. Wired Area Node