📁 Paper 2 · 3.5 Computer Networks
3.5a Network Types — LAN, WAN & PAN
AQA 8525 · GCSE Computer Science · ~10 min read
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Quiz

What is a Network?

A network is two or more computers (or devices) connected together to share resources and communicate. Networks can be connected via cables (wired) or wireless signals (Wi-Fi, Bluetooth).

✓ Advantages of networking

  • Share files and data between users easily
  • Share an internet connection (one ISP link serves many devices)
  • Share hardware (printers, scanners, servers)
  • Centralised backups and data storage
  • Centralised user authentication (login once for all resources)
  • Install software once on a server, deploy to all devices

✗ Disadvantages of networking

  • Security risk — malware can spread across the network
  • Expensive to set up (cables, switches, servers)
  • Requires a network administrator to manage
  • Server failure can affect all users (single point of failure)
  • Confidential data at risk if the network is hacked

Types of Network

🏢

LAN — Local Area Network

Small geographic area — single building or site (school, office, home).

Typically owned by one organisation.

Connected by Ethernet cables or Wi-Fi.

High speed: up to 10 Gbps (Gigabit Ethernet).

Examples: School network, home Wi-Fi, office LAN

🌍

WAN — Wide Area Network

Large geographic area — city, country, or global.

Connects multiple LANs together.

Uses leased/public infrastructure (fibre, telephone lines, satellites).

Slower than LAN and more expensive.

Example: The Internet is the largest WAN.

📱

PAN — Personal Area Network

Very small area around one person (up to ~10 metres).

Connects personal devices wirelessly (usually Bluetooth).

Low power, short range.

Examples: Phone + earbuds + smartwatch + laptop all connected via Bluetooth

LAN vs WAN — Comparison

FeatureLANWAN
Geographic areaSmall (single site/building)Large (city, country, global)
OwnershipOne organisation (private)Leased from ISP / public infrastructure
SpeedVery fast (up to 10 Gbps)Slower (varies by technology)
Cost to set upLowerHigher (leasing costs)
Typical connectionsEthernet cables, Wi-FiFibre-optic lines, telephone lines, satellites
Security controlMore control (private)Less control (public infrastructure)
ExampleSchool networkThe Internet

The Internet vs an Intranet

FeatureInternetIntranet
What is it?Global public network of networksPrivate internal network (within an organisation)
AccessAnyone with internet accessAuthorised users only (employees, students)
TechnologyUses TCP/IP protocolsUses the same web technology but restricted access
ExamplesWebsites, email, streamingSchool VLE, company internal portal, HR systems

Wired vs Wireless

Wired (Ethernet)Wireless (Wi-Fi)
SpeedVery fast and consistent (up to 10 Gbps)Slower, varies with distance and interference
SecurityMore secure — physically tapping a cable is hardLess secure — signals can be intercepted
ReliabilityVery reliable — no interferenceCan be affected by walls, devices, interference
MobilityFixed — devices cannot moveDevices can move within the coverage area
CostHigher setup cost (cables, switches)Lower setup cost (just a router/AP needed)
Exam tip: The most common exam question is to compare LAN and WAN with examples. Remember: LAN = small area, one owner, fast, cheap. WAN = large area, leased infrastructure, slower, expensive. The Internet is the world's largest WAN. An intranet uses the same technology as the internet but is private.
⚠️ Common Mistakes
  • Confusing the Internet with an intranet — the Internet is public/global; an intranet is private/internal
  • Saying WAN is always slow — WAN can be fast (modern fibre-optic WANs), but it is generally slower than a LAN on the same site
  • PAN is often forgotten — always mention Bluetooth phone/earbuds as a classic PAN example
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Video coming soon

Key points

  • Network: 2+ devices connected to share resources; advantages: share files, internet, hardware; disadvantages: security, cost, admin
  • LAN: small area, one organisation, fast, Ethernet/Wi-Fi (school/home)
  • WAN: large area, leased infrastructure, slower, connects LANs (Internet = largest WAN)
  • PAN: personal devices, Bluetooth, ~10m range (phone + earbuds + watch)
  • Internet = global public; Intranet = private internal using same technology
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Worksheet — 3.5a Network Types

8 questions · 18 marks

Q1What is a computer network?[1]
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Two or more computers/devices connected together to share resources and communicate [1].
Q2Give two advantages of connecting computers in a network.[2]
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Any two: share files/data [1]; share internet connection [1]; share hardware (printers) [1]; centralised backups [1]; centralised user authentication [1].
Q3Describe a LAN and give one example.[2]
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A Local Area Network covers a small geographic area (single building or site) [1]; owned by one organisation, typically connected via Ethernet cables or Wi-Fi; example: school network, home network, or office LAN [1].
Q4Describe a WAN. Give one example of a WAN.[2]
✅ Mark scheme
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A Wide Area Network covers a large geographic area (city, country, or global) [1]; uses leased/public infrastructure (telephone lines, fibre, satellites) to connect multiple LANs; example: the Internet [1].
Q5State two differences between a LAN and a WAN.[2]
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Any two: LAN is a small area / WAN is a large area [1]; LAN is owned by one organisation / WAN uses leased public infrastructure [1]; LAN is generally faster / WAN is slower [1]; LAN is cheaper to set up / WAN is more expensive [1].
Q6What is a PAN? Give a real-world example of a PAN in use.[2]
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A Personal Area Network connects personal devices around a single person, typically within 10 metres [1]; example: a phone connected via Bluetooth to wireless earbuds and a smartwatch [1].
Q7Explain the difference between the Internet and an intranet.[3]
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The Internet is a global public network of interconnected networks accessible by anyone with internet access [1]; an intranet is a private internal network (within an organisation) that uses the same web technology but is restricted to authorised users (e.g. employees, students) [1]; example: a school's VLE or a company's internal HR portal [1].
Q8A school is deciding between wired and wireless networking for its classrooms. Discuss the advantages and disadvantages of each approach.[4]
✅ Mark scheme
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Wired advantages: faster and more consistent speeds [1]; more secure (signals cannot be intercepted) [1]. Wired disadvantages: expensive to install (cables and switches) [1]; devices cannot move [1]. Wireless advantages: cheap/easy to set up; devices can move freely [1]; Wireless disadvantages: slower and can suffer interference; less secure [1]. (Any 4 valid points)
✓
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Mini Test — 3.5a Network Types

Timed exam conditions.

  • 8 questions · 10 minutes
  • 5 MCQ + 3 short answer
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