We use essential cookies to sign you in and remember your settings. With your permission we also use analytics cookies to understand how the site is used. See our privacy policy or fine-tune this anytime at cookie settings.

SubjectFree lesson

Computer networks

ClassNotes Team 4 MIN READUPDATED 17 JUN 2026

WEEK 2 & 3

Topic: Computer networks

Objectives:

At the end of the lesson, Pupils should be able to:

  1. Define computer net- computer net-
  2. List the types of computers

CONTENT

A computer network

A computer network is a group of two or more computers connected so that they can share resources like hardware, software and data. Computers in a network can communicate with one another.

A computer network is the interconnection of computers and other telecommunication devices for the purpose of sharing resources. Some sources that can be shared in such interconnections include files and folders, programs, printers, hard disk, processor, etc.

 

When computers are interconnected through a central computer, communication links between users become easier. This could enable them to exchange information freely with each other, and also allow a common use of components.

In a network environment, when there is a centrally located computer to which all other computers are connected, it is called HOSTCOMPUTER or SERVER. The other computers connected to such a computer are called TERMINALS or WORKSTATIONS.

There are three types of computer network e.g. Local Area Network, Metropolitan Area Network, and Wide Area Network.

IMPORTANCE OF COMPUTER NETWORK

A computer network is important for the following reasons.

1. It enables users to access files or programs from another computer without carrying a disk.

2. It enable computer to print documents on a printer attached to another computer

3. It enables users to be able to send messages by using electronic mail (email).

4. It can help users gain easy access to the internet.

 

There are three types of hardware needed for a computer network for the purpose of data communication. They are:

1. Central processor.

There must be a computer, otherwise called the HOST Computer, that has a central processor.

2. Terminals or work stations.

These are the other computers that are connected to a server or central computer.

3. Communication channels

Communication channels refer to things that could link different systems together. Examples are: cables, telephones, satellite stations, etc.

Types of networks

The two types of computer networks are:

1 Local Area Networks (LAN); and

2 Wide Area Networks (WAN)

 

Local Area Networks

LAN consists of a collection of microcomputers that can share peripherals and information. They can also communicate with each other on the network.

Microcomputers in a LAN are usually in the same building or a school. Each microcomputer in a LAN  can work both as an independent personal computer running its own software and as a workstation. A LAN has a network server. This runs the network operating system, which allows resources to be shared with other computers on the network. Each computer on a LAN is known as a client. The devices shared by a LAN are printers, hard disk drives, disk drives, CD-ROM drives, modems and fax machines.

Advantages of a LAN

1 Software and data files can be shared by many users.

2 It is usually cheaper to buy one copy of a software application and pay the license fee for several machines than to buy individual packages for each computer.

3 Users can work together on a single document from different parts of the network (though not at the same time).

4 Users can communicate with other users on the network using email.

Wide Area Networks (WANs)

A WAN connects networks across a large geographical area such as a city, state or country. Information can be transmitted using special high-speed telephone lines, microwave links, satellite links or a combination of all these. WANs are used in universities, research centres, companies, and banks, allowing information to be shared across a country or multiple countries.

Metropolitan Area Network (MAN)

This type of network is mostly used by Radio and Television stations. In this case, computers are interconnected within a wider geographical area, such as a town, city, or state, for data communication.

ASSESSMENT AND EVALUATION

i) Define computer net- computer net-

ii) List the types of computers

CONCLUSION: The teacher goes over the topic once again for better understanding

Activity

1 What is the difference between a server and a client in a LAN?

2 Mention 5 organisations where LANs are used.

3 Mention 5 organisations where WANs are used.