Networks (Edexcel GCSE Computer Science): Revision Notes

Networks

What are networks?

A network is a system that connects two or more computing devices together so they can communicate and share resources with each other. Think of it like a digital highway system that allows computers to send information back and forth. Networks can be different sizes depending on how much area they need to cover - from a small home setup to connections spanning entire countries.

Why do we connect computers in networks?

There are several important reasons why businesses, schools, and homes set up computer networks:

• Sharing resources and data - Instead of having separate printers, hard drives, and software on every computer, networks let multiple users share these resources. This saves money and makes management much easier.

• Internet access and web services - Networks provide shared internet connections and access to web-based software and services that everyone can use.

• Centralised support and backup - IT teams can manage all computers from one central location, install updates, and back up important data automatically across the network.

• Communication and collaboration - Networks enable email, video conferencing, instant messaging, and shared file systems that help people work together effectively.

• Quick software deployment - New programmes and security updates can be installed on all network computers simultaneously, rather than having to update each machine individually.

Local area networks (LANs)

A local area network connects devices within a small geographical area - typically within a single building or group of buildings on the same site. LANs are perfect for homes, schools, offices, and small businesses where all the computers are relatively close together.

Many homes now have LANs too, often created using a wireless router that allows family members to share an internet connection and access shared files or printers. These home networks make it easy for laptops, tablets, phones, and desktop computers to all work together.

Wide area networks (WANs)

Wide area networks connect separate LANs across large geographical distances to create a "network of networks." Large companies often use WANs to link their offices in different cities or countries, allowing employees everywhere to access the same systems and share information.

The diagram shows how a WAN works - multiple LANs in different locations all connect to a central WAN infrastructure. Each LAN might serve a different office building or branch, but they can all communicate with each other through the WAN connection.

Companies use WANs to share resources and data between their different locations. For example, a retail chain might use a WAN to connect their head office computer systems with all their individual stores, allowing them to track inventory, process sales, and manage operations across hundreds of locations.

The internet as a WAN

The internet itself is actually a massive example of a WAN - it's a global system of interconnected computer networks that spans the entire world. When you use hyperlinks to jump from a website on one continent to a server on another, you're travelling across this enormous WAN.

Network components and infrastructure

Networks use several types of specialised equipment to function properly:

• Network servers store important data and manage network services
• LAN switches connect multiple devices within a local network
• Gateway routers manage traffic between different networks and provide internet access
• Network users are the individual computers and devices that people use to access the network

These components work together to ensure data can flow efficiently between all connected devices, whether they're in the same room or on different continents.

Real-world example