Explain the client-server and peer-to-peer models of networked computers

What is a Network?

A network is a group of computers that can talk to each other. Think of it like a telephone network where you can call friends, but instead of voices, computers send data packets.

Client‑Server Model

Imagine a restaurant:

• Client (you) – places an order.
• Server (chef) – prepares the food.
• Network – the kitchen staff passing the order and the food.

In a computer network, the client requests a service (e.g., a web page). The server processes the request and sends back the data.

Key points:

1. Centralised control – one or a few servers.
2. Clients are usually less powerful.
3. Scalable – add more servers to handle more clients.

Peer‑to‑Peer (P2P) Model

Think of a potluck dinner:

• Everyone brings a dish (data).
• No single host is responsible for everything.
• Each participant can both request and provide food.

In P2P networks, each computer (peer) can act as both client and server. Examples: file sharing (BitTorrent), some VoIP services.

Key points:

1. Decentralised – no single point of failure.
2. Peers share resources directly.
3. Can be less secure if peers are not trusted.

Comparison Table

Exam Tips 💡

• Remember the analogy of a restaurant for client‑server and a potluck for P2P.
• Be able to list three key differences (control, scalability, security).
• Use the table format if you need to compare features quickly.
• When asked to draw a diagram, label the client, server, and network clearly.
• Practice explaining both models in one sentence each.