If you are getting broadband for the first time and want to connect different computers in different rooms to the service, buying an ADSL Wi-Fi router is a great idea because it's cheaper and easier than upgrading later.

A Wi-Fi router is just a high-speed modem and Wi-Fi transmitter all in one box.

The other advantage of buying a Wi-Fi router is that it does not need a computer to run it.

In other words, the router can be plugged directly into the phone socket and your desktop or laptop machines will have access to broadband wherever they are.

This can be useful if your main computer and phone socket are in different places. It also means you don't need to keep your main computer running all the time.

SOURCE  http://www.bbc.co.uk