DIGITAL TECHNOLOGY: Basic Computer Communication Networks

JSS 2 Class Note

Core Concepts

Imagine you have many computers, and you want them to talk to each other, share files, or use the same printer. A computer network is simply a group of two or more computers linked together. These links can be through cables or wirelessly, like Wi-Fi. The main idea is to let them share information and resources easily.

Key Points

Meaning of Networks

A computer network is a system that connects computers and other devices (like printers or mobile phones) so they can communicate and share data. Think of it like a road system connecting different houses, allowing people to visit each other and exchange goods.

Need for Networks

Networks are very important in today's world because they help us:

1. Share Resources: Instead of buying a separate printer for every computer, all computers on a network can share one printer. This saves money and space.
2. Share Information: You can easily send files, documents, pictures, and videos from one computer to another on the network without using a flash drive.
3. Communicate: Networks allow people to send emails, chat messages, or make video calls with others, whether they are in the same room or far away.
4. Access the Internet: To connect to the internet, your computer is part of a very large network.
5. Save Money: Sharing software licenses or internet connections among many users becomes possible and more affordable.

Network Types

Computer networks are classified based on how large an area they cover:

1. LAN (Local Area Network)

   • Meaning: A LAN connects computers in a small, limited geographical area.
   • Coverage: This could be a single room, a home, an office building, or a school campus.
   • Example: All the computers in your school's computer lab connected together form a LAN. A Wi-Fi network in your house is also a LAN.
   • Speed: LANs are usually very fast because the distances are short.
   • Ownership: They are typically owned and managed by an individual or a single organization.

2. MAN (Metropolitan Area Network)

   • Meaning: A MAN is larger than a LAN but smaller than a WAN. It connects computers across an entire city or a large campus with multiple buildings.
   • Coverage: It covers an area the size of a town or city.
   • Example: A network connecting all the branches of a bank within Lagos city, or a university connecting its different faculties spread across the city.
   • Speed: MANs offer moderate to high speeds.
   • Ownership: Often owned by a single organization or a service provider who offers networking services to businesses in the city.

3. WAN (Wide Area Network)

   • Meaning: A WAN connects computers over very large geographical areas. These areas can span across states, countries, or even continents.
   • Coverage: It covers vast distances, sometimes using public telecommunication lines, satellites, or dedicated cables.
   • Example: The Internet is the best example of a WAN, connecting millions of computers worldwide. A company with offices in Abuja, Port Harcourt, and Kano would use a WAN to connect them.
   • Speed: WAN speeds can vary and are generally slower than LANs due to the long distances data has to travel.
   • Ownership: Typically involves multiple organizations or public carriers (like telecommunication companies) to manage the vast infrastructure.

Summary

Computer networks link devices together for sharing resources and information, and for communication. They are essential for modern life. Networks come in different sizes: LANs for small areas like a school, MANs for a city, and WANs for very large areas like countries or the entire world (the Internet). Each type serves a specific purpose based on the distance and number of devices it needs to connect.