OCR J277 · Component 1 · Topic 1.3.1b

Network Types & LAN Hardware

Client-Server · Peer-to-Peer · Wireless Access Points · Routers · Switches · NICs · Transmission Media

CSZone OCR GCSE Computer Science J277

Learning Objectives

By the end of this video you will be able to...

Describe the roles of computers in a client-server network, including examples of servers providing services

Describe the roles of computers in a peer-to-peer network, and compare it to client-server

State the purpose of a wireless access point and a router

State the purpose of a switch and a NIC (Network Interface Controller/Card)

Describe the role of transmission media in connecting devices

⚡ This is part 2 of 4 covering 1.3.1 — Networks and topologies.

Client-Server Networks

One computer provides, the others request

DEFINITION

In a client-server network, a dedicated server provides services or resources to other computers, which are called clients.

A server provides a service — for example, a web server provides web pages, a file server provides file storage and retrieval, and a print server manages access to printers.

A client is a computer that requests and uses services from the server. A school computer asking the file server for a saved document is a client making a request.

⚡ Key concept from the spec: the server provides services; the client requests and uses those services. Know both sides.

Peer-to-Peer Networks

All computers are equal

DEFINITION

In a peer-to-peer (P2P) network, all computers have equal status — there is no dedicated server. Each computer, called a peer, can both provide and request resources from the others.

Because there is no central server, each peer manages its own resources — files, storage, and processing — and can share them directly with other peers on the network.

Common examples: a small home network where two computers share files directly, or peer-to-peer file sharing applications where files are distributed across many users' devices.

⚡ P2P is simpler and cheaper to set up than client-server — no dedicated server hardware or software needed — but harder to manage as the network grows.

Comparing Network Types

Client-server vs peer-to-peer

	Client-Server	Peer-to-Peer
Control	Centralised — managed by the server	Decentralised — each peer manages itself

Setup cost

Higher — dedicated server hardware needed

Lower — no dedicated server needed

Typical use

Schools, businesses, large networks

Small home networks, file-sharing apps

⚡ Exam tip: when comparing, always give the same feature for both types — don't just describe one. State the difference directly.

LAN Hardware

Wireless Access Point (WAP)

📶

WIRELESS ACCESS POINT

A device that allows wireless devices — such as laptops, phones and tablets — to connect to a wired network using Wi-Fi.

A WAP acts as a bridge between wireless devices and the wired network. It receives wireless signals from devices and passes them onto the wired network, and vice versa.

Common examples include the Wi-Fi router in a home (which has a built-in access point), or separate WAPs installed across a school or office building to extend wireless coverage.

⚡ A WAP does not route data between networks — that's the router's job. The WAP's role is specifically to provide a wireless connection point.

LAN Hardware

Router

🌐

ROUTER

A device that routes data packets between different networks — for example, between a home LAN and the Internet.

A router examines the destination IP address of each data packet and determines the best path for it to travel across the network or to reach another network.

Without a router, devices on a local network could not communicate with devices on other networks such as the Internet. The router is the gateway between the LAN and the wider network.

⚡ Key distinction: a router connects different networks together; a switch connects devices within the same network.

LAN Hardware

Switch

🔀

SWITCH

A device that connects multiple devices within the same network and directs data to the correct device, rather than broadcasting it to all devices.

A switch uses the MAC address of each device to direct data packets to the intended recipient only. This makes the network more efficient, because not every device receives every packet.

Switches are commonly used in schools and offices to connect computers, printers and servers within the same LAN. A switch does not connect to the Internet — that's the router's role.

⚡ Router → connects different networks. Switch → connects devices within the same network. This distinction appears frequently in exam questions.

LAN Hardware

NIC — Network Interface Controller/Card

🖧

NIC (NETWORK INTERFACE CONTROLLER/CARD)

A hardware component that allows a device to connect to a network. Every device on a network must have a NIC.

Each NIC is assigned a unique MAC address (Media Access Control address) when it is manufactured. This address permanently identifies the device on the network.

NICs can be wired — connecting via an Ethernet cable — or wireless — connecting via Wi-Fi. Many modern devices have both types built in.

⚡ The NIC is what physically enables a device to communicate on a network at all. Without a NIC, a device simply cannot connect.

LAN Hardware

Transmission Media

DEFINITION

Transmission media are the physical or wireless channels through which data travels between devices on a network.

🔌

WIRED (e.g. Ethernet / copper cable)

Data travels through physical cables. Generally faster and more reliable than wireless, with less interference. Used in offices, schools, and data centres.

📡

WIRELESS (e.g. Wi-Fi / radio waves)

Data travels through radio waves. No physical cable needed — devices can connect from anywhere in range. More convenient but can be affected by interference and distance.

⚡ "Transmission media" is the umbrella term for how data physically moves between devices — the spec expects you to know both wired and wireless as types.

Exam Practice

Exam-Style Questions — Network Types & Hardware

Question 1 · 2 marks

Describe the role of a server in a client-server network.

2 marks

ANS

A server provides services or resources to other computers (clients) on the network. For example, a file server provides file storage and retrieval, and a web server provides web pages.

Question 2 · 2 marks

State one difference between a router and a switch.

2 marks

ANS

A router connects different networks together (e.g. a LAN to the Internet), whereas a switch connects devices within the same network and directs data to the correct device.

Question 3 · 3 marks

A school is setting up a new computer room. Identify and describe three pieces of hardware that would be needed to connect the computers into a LAN.

3 marks

ANS

Any three from: NIC (allows devices to connect to the network); Switch (directs data between devices in the LAN); Router (connects the LAN to the Internet); WAP (allows wireless devices to connect).

Common Mistakes

Four mistakes that cost marks

Confusing a router with a switch. A router connects different networks together (e.g. your LAN to the Internet). A switch connects devices within the same network. Don't use them interchangeably in an answer.

Saying a WAP "provides internet access." A WAP provides a wireless connection to the network — it doesn't provide internet access by itself. The router connects to the internet.

Describing peer-to-peer as "less secure" without explaining why. In P2P, each computer manages its own security — there is no central point controlling access. Without that central control, it can be harder to enforce consistent security policies.

Forgetting what NIC stands for. NIC = Network Interface Controller (or Network Interface Card). It's the hardware that allows a device to connect to a network at all. Every networked device needs one.

Summary

1.3.1b — Network Types & LAN Hardware

CLIENT-SERVER

Server provides services. Client requests and uses them. Centralised control.

PEER-TO-PEER

All peers equal. No dedicated server. Decentralised control.

WAP / ROUTER / SWITCH

WAP: wireless access. Router: route between networks. Switch: direct within a network.

NIC / TRANSMISSION MEDIA

NIC: lets a device connect. Media: wired (Ethernet) or wireless (Wi-Fi/radio waves).

⚡ Exam tip: for each hardware component, know its name, what it does, and where you'd find it in a typical school or office LAN.

Network Types & LAN Hardware

By the end of this video you will be able to...

One computer provides, the others request

All computers are equal

Client-server vs peer-to-peer

Wireless Access Point (WAP)

Router

Switch

NIC — Network Interface Controller/Card

Transmission Media

Exam-Style Questions — Network Types & Hardware

Four mistakes that cost marks

1.3.1b — Network Types & LAN Hardware

That's 1.3.1b done.