Series 4 — Free Theory
Computer Networks
Six lessons covering everything you need for networks in GCSE Computer Science. From the difference between a LAN and a WAN, through topologies, protocols and packet switching, to network security and threats. Interactive, exam-focused, and free.
Start Lesson 1All 6 Lessons
Work through in order or jump to a topic. Each lesson has interactive tools, a drag activity, a 5-question quiz, printable worksheets, and a full teacher panel.
1
What is a Network?
LAN vs WAN, why networks exist, network hardware devices (router, switch, hub, WAP, NIC, modem), client-server vs peer-to-peer.
2
Network Topologies
Star, bus, mesh and ring topologies. Advantages, disadvantages and fault tolerance. How to draw and annotate network diagrams.
3
Wired & Wireless Networks
Ethernet, coaxial and fibre optic cables. Wi-Fi, Bluetooth and NFC. Comparing speed, security, cost and reliability of each medium.
4
The Internet & How Data Travels
IP addresses (IPv4 and IPv6), MAC addresses, DNS, DHCP, packet switching, and how a packet finds its way across the internet.
5
Protocols & Layers
HTTP, HTTPS, FTP, SMTP, IMAP, POP3. The TCP/IP four-layer model. Why protocols exist and what happens when they interact.
6
Network Security
Malware, phishing, brute force, DoS, man-in-the-middle. Defences: firewalls, encryption, 2FA, anti-malware, access control, and penetration testing.
Topics covered across the series
LAN and WAN
Network hardware devices
Client-server & P2P
Star, bus, mesh, ring topologies
Ethernet and fibre optic
Wi-Fi and Bluetooth
IPv4 and IPv6 addresses
MAC addresses
DNS and DHCP
Packet switching
HTTP, HTTPS, FTP, SMTP
TCP/IP four-layer model
Malware and phishing
Firewalls and encryption
Network performance factors
Two-factor authentication
Networks Flashcard Deck
All key vocabulary across all 6 lessons. Filter by lesson, flip to reveal definitions, mark terms as known.
Exam Practice Questions
10 MCQ + 5 written questions covering all 6 lessons. Instant MCQ feedback and mark schemes for written answers.