Types of Networks (LAN, WAN, PAN)

A computer network is two or more computing devices connected together so that they can communicate and share resources. Networks are fundamental to modern computing — from the small Bluetooth connection between your phone and headphones to the global infrastructure of the internet.

This lesson covers the three main types of network you need to know for GCSE Computer Science: LAN, WAN and PAN.

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Local Area Network (LAN)

A Local Area Network (LAN) covers a small geographical area, typically a single building or a campus of buildings. Examples include:

• A school network connecting all the computers in the building
• An office network linking workstations, printers and servers
• A home network connecting a laptop, phone, smart TV and printer

Key characteristics of a LAN

Feature	Detail
Geographical size	Small — a single building or site
Ownership	Owned and maintained by the organisation or individual that uses it
Hardware	Typically uses switches, wireless access points and a router
Connection media	Ethernet cables (copper or fibre optic) and/or Wi-Fi
Speed	Generally high speed (100 Mbps to 10 Gbps on modern networks)
Cost	Low ongoing cost once installed, because the organisation owns the infrastructure

Benefits of a LAN

• Resource sharing — printers, scanners and file storage can be shared between users.
• Internet sharing — a single broadband connection can be shared via a router.
• Centralised data — files stored on a server can be accessed from any workstation and backed up centrally.
• Communication — users can send messages, emails and share calendars internally.
• Software deployment — software can be installed and updated centrally across all machines.

Drawbacks of a LAN

• Security risk — if one machine is infected with malware, it can spread across the network.
• Setup cost — purchasing switches, cabling and servers requires an initial investment.
• Management — a network manager or technician may be needed to maintain the network.
• Single point of failure — if the central server or switch fails, the whole network may go down.

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Wide Area Network (WAN)

A Wide Area Network (WAN) connects computers and LANs over a large geographical area — a city, a country or even the entire world. The internet is the largest and best-known example of a WAN.

Key characteristics of a WAN

Feature	Detail
Geographical size	Large — cities, countries, continents
Ownership	Uses infrastructure owned by third parties, such as telecommunication companies
Hardware	Routers, leased lines, satellite links, undersea cables
Connection media	Fibre optic cables, telephone lines, satellite, microwave links
Speed	Varies — can be slower than a LAN due to distance and congestion
Cost	Higher ongoing cost because of leased lines and third-party infrastructure

Examples of WANs

• The internet — a global WAN connecting billions of devices.
• A company connecting its London and New York offices over a leased line.
• An ATM (cash machine) network linking thousands of machines to a central bank server.

Differences between LAN and WAN

	LAN	WAN
Area	Small (single building/site)	Large (city/country/global)
Ownership	Owned by the organisation	Uses third-party infrastructure
Speed	Typically faster	Typically slower
Cost	Lower running costs	Higher running costs
Security	Easier to secure	Harder to secure due to scale

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Personal Area Network (PAN)

A Personal Area Network (PAN) is the smallest type of network and covers the area immediately around an individual person, typically within a few metres.

Examples of PANs

• Connecting a smartphone to wireless earbuds via Bluetooth
• Linking a laptop to a mobile phone for tethering (using the phone's data connection)
• Syncing a smartwatch with a phone

Key characteristics of a PAN

Feature	Detail
Geographical size	Very small — typically within a few metres
Connection	Usually Bluetooth or USB
Devices	Personal devices (phone, tablet, headphones, smartwatch)
Speed	Relatively low compared to LAN

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Client-Server vs Peer-to-Peer Networks

Networks can also be classified by how they are organised:

Client-Server Network

In a client-server network, one or more powerful computers called servers provide services (files, printing, email, web pages) to other computers called clients.

• The server is always on and manages shared resources.
• User accounts, security and backups are managed centrally on the server.
• Used in schools, businesses and the internet.

Peer-to-Peer Network (P2P)

In a peer-to-peer network, all computers are equal — there is no dedicated server. Each device can act as both a client and a server.

• Easy and cheap to set up.
• No central management — each user is responsible for their own machine.
• Suitable for small networks (e.g. a home network or small office).
• Security is harder to manage because there is no central control.

Feature	Client-Server	Peer-to-Peer
Central server	Yes	No
Security	Centralised, easier to manage	Decentralised, harder to manage
Backup	Centrally managed	Each user backs up their own files
Cost	More expensive (server hardware and software)	Cheaper to set up
Best for	Large organisations	Small networks or home use

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Summary

• A LAN is a network covering a small area, owned by the organisation.
• A WAN covers a large area and typically uses third-party infrastructure.
• A PAN is a very small network around an individual, often using Bluetooth.
• Networks can be organised as client-server (centralised) or peer-to-peer (decentralised).

Exam Tip: You may be asked to compare LAN and WAN. Make sure you can describe at least three differences, covering area, ownership and speed.