Network
Types

LAN · WAN · PAN · Client-Server · Peer-to-Peer

CSZoneAQA GCSE Computer Science 8525

LAN vs WAN vs PAN

Networks by Geographic Scale

Network	Stands for	Scale	Example
LAN	Local Area Network	Single site	School, office, home
WAN	Wide Area Network	Multiple sites / global	The Internet, bank branches
PAN	Personal Area Network	Very small (person)	Bluetooth headset + phone

Key:LANs connect devices in one location. WANs connect multiple LANs across large distances (e.g. leased fibre lines).

Client-Server vs Peer-to-Peer

Two Network Models

CLIENT-SERVER

A central server provides services; clients request them. Centralised control and administration. Used in schools, businesses.

Advantages: central backup, security, shared resources

PEER-TO-PEER (P2P)

All devices are equal — each can act as client and server. No central control. Used for file sharing (torrents), some home networks.

Advantages: no single point of failure, cheaper (no dedicated server)

Factors Affecting Network Performance

What Makes a Network Fast or Slow?

Bandwidth — maximum data transfer rate (Mbps/Gbps). Higher = faster

Latency — delay between sending and receiving. Lower = better

Number of users — more users sharing a connection = slower for each

Transmission medium — fibre optic > copper cable > Wi-Fi (generally)

Network hardware — router/switch quality affects routing efficiency

Exam Practice

Have a go at this question

AQA-style question

Explain the difference between a LAN and a WAN.

2 marks

A LAN (Local Area Network) connects devices within a single site or small geographic area such as a school or office [1]. A WAN (Wide Area Network) connects multiple sites across large distances — often using leased lines from telecommunications companies — such as the Internet connecting countries globally [1].

Key Takeaways

What to Remember

LAN = single site · WAN = multiple sites / global · PAN = personal (Bluetooth)

Client-server: centralised, secure, managed. Used in schools/businesses

P2P: no central server, devices equal, cheaper, used for file sharing

Network speed depends on: bandwidth, latency, users, medium, hardware