WJEC GCSE Computer Science Computer networks and the internet: a complete overview of networks, hardware, protocols and addressing

What the Computer networks and the internet content demands

This area is where WJEC checks that you understand how computers connect and communicate, from a single school LAN to the global internet. The hardware roles (switch versus router), the protocol purposes, and the IP-versus-MAC and DNS questions appear repeatedly, so precise definitions earn marks reliably. The content links to cyber security (data travelling between machines must be protected) and to data representation (everything sent is binary, broken into packets).

This guide walks through the Computer networks and the internet content and ties together the matching dot-point pages, each of which has its own worked examples and practice questions.

Networks and topologies

A network connects computers to share resources and communicate. A LAN covers a small area like one building; a WAN covers a large area like across countries, and the internet is the largest WAN. In client-server networks, servers provide services to clients (central control, but the server is a single point of failure); in peer-to-peer networks all computers are equal and share directly (cheaper but harder to manage). A topology is the layout: a star connects all devices to a central switch; a bus connects them along one cable.

Network hardware and transmission

A NIC connects a device to a network and has a unique MAC address. A switch connects devices within a LAN and forwards data only to the intended device; a router connects different networks and routes data between them. Connections are wired (fast, reliable, secure) or wireless (mobile and convenient but slower and less secure). Bandwidth is the amount of data sent per second. Data travels in packets, each with addressing information, reassembled at the destination, so a lost packet can be resent.

Protocols and layers

A protocol is a set of rules for how devices communicate. TCP/IP is the core internet set: IP addresses and routes packets, TCP splits data into packets, checks delivery and reorders them. HTTP transfers web pages, HTTPS is the encrypted version for sensitive data, FTP transfers files and SMTP sends email. Communication is organised into layers, each handling one part of the job, which makes networks easier to design and maintain and lets equipment from different makers work together.

IP addresses and routing

An IP address identifies a device and routes data to it across networks and can change; a MAC address is unique, permanent and tied to the hardware, used on the local network. The Domain Name System translates domain names into IP addresses so people can type names. Routers read the destination IP address on each packet and forward it hop by hop across the internet. The internet is the global network of networks; the web is one service running on it.

Check your knowledge

A mix of network, hardware, protocol and addressing questions covering the Computer networks and the internet content. Attempt them under timed conditions, then check against the solutions.

1. State the difference between a LAN and a WAN. (2 marks)
2. Give one advantage and one disadvantage of a star topology. (2 marks)
3. State the purpose of a router. (1 mark)
4. State what bandwidth measures. (1 mark)
5. Give one benefit of sending data in packets. (1 mark)
6. State the purpose of HTTPS and how it differs from HTTP. (2 marks)
7. State one difference between an IP address and a MAC address. (1 mark)
8. Describe what DNS does. (2 marks)