GCSE-ready- Home
- Lessons
- GCSE & IGCSE Computer Science
- Networks, LANs, WANs and the internet
Networks, LANs, WANs and the internet
🎬 The doodle video for this lesson is coming soon. Subscribe on YouTube to see it first.
Connecting computers lets people share files, devices and ideas. The internet is the biggest network of all.
Why network?
Share files and data, and work together on them.
Share resources such as printers and an internet connection.
Communicate by email and messaging.
Central backup and security updates.
Drawbacks: malware can spread, data can be attacked, and setting up costs money.
Share resources such as printers and an internet connection.
Communicate by email and messaging.
Central backup and security updates.
Drawbacks: malware can spread, data can be attacked, and setting up costs money.
LAN and WAN
A LAN (local area network) covers a small area such as a home, school or office. The owner usually owns the equipment.
A WAN (wide area network) covers a large geographical area and connects LANs together, often using equipment owned by telecommunications companies.
The internet is a global WAN: a network of networks.
A WAN (wide area network) covers a large geographical area and connects LANs together, often using equipment owned by telecommunications companies.
The internet is a global WAN: a network of networks.
How the internet is structured
Every device on the internet has an IP address, such as 192.168.1.20 (IPv4 uses four numbers from 0 to 255).
Data is split into packets. Each packet carries the sender's and receiver's IP addresses.
Routers read the destination address and forward each packet towards its destination, network by network. Packets may take different routes.
Data is split into packets. Each packet carries the sender's and receiver's IP addresses.
Routers read the destination address and forward each packet towards its destination, network by network. Packets may take different routes.
A school has 300 computers on one site and connects to its other campus 40 km away. Identify the types of network.
- The computers on one site form a LAN.
- Connecting two distant sites uses a WAN.
Answer: A LAN on each site, linked by a WAN
Networks share data, resources and communication. LANs cover small areas; WANs cover large areas and link LANs. The internet is a global WAN where routers forward packets using IP addresses.
Check you have got it
Answer 6 quick questions with instant marking. If you get one wrong, GCSE-ready shows you why and gives you another go. It is free, and you do not need an account.