Client / Server Model


The job of a server is to provide services to the clients on the network.

The services that a server might provide include:

  • User Authentication
  • File Storage
  • Internet Access
  • Hardware sharing ( printers, scanners,etc)


The job of the client is to provide a workstation for networks users to use.

When a user logs in to a client they are usually provided with access to:

  • a private files storage area
  • a shared file storage
  • the internet and the organisation’s intranet.
  • Network hardware resources, such as printers and scanners.
The Client Server Model. Source: Wikipedia

Network Interface Controller / Card

All servers and clients need to have a network interface card to access the network.

Network interface cards a machine to connect to a network using an Ethernet cable.


Switches and hubs

With a small network you might get away with connecting all of your clients directly to the server, but larger networks require hubs/switches in between to control the flow of data within the network.



The job of a router is to connect two different types of network together. Within most organisations a router is used to connect the internal Local Area Network to the Internet.

Home networking

You home broadband often comes with what the broadband companies call a ‘router’, these are actually composite devices that combine:

  • A Router
  • A Firewall
  • A Wireless Network Access Point
  • A Wired Network Switch


Ad-Hoc Networks

Ad hoc networks are peer-to-peer networks ( not client / server) that are usually temporary and quick to set up. They are usually used for temporary file and resource sharing, where a larger client-server network is not needed. Each device connected to an Ad-Hoc network is a ‘node’, and each node forwards on data to all other nodes in range.


  • Quick, easy and cheap to set up – no server, switch or routers required.
  • Decentralised, meaning that if one ‘node’ goes down, the network still remains up.


  • No access the the facilities that servers provide ( file backup, use authentication)
  • Less secure than standard networks