All broadband accounts allow for multiple connections to the Internet. However, you will need a network device - like a router - to achieve it. Standard cable DSL modems are designed to allow one connection. The ADSL modem plugs into the telephone socket, and then contains one USB connection to the computer.
Routers work in a similar fashion, it plugs into the telephone socket, but it then contains multiple ethernet hubs to connect to four or more computers. Recently wireless routers have been released. Therefore, when it comes to routers, you currently have two options:
Wireless routers have the advantage of free roaming for it's users. With a netgear router, currently costing £30, it allows up to 253 users to connect to the router. Which will then connect to the Internet via one IP address and service account. Of course, most UK access accounts would not have a download speed capable of handling 253 users. But, this may change as super fast broadband is rolled out across the UK.
The one downside to wireless routers is security. While most routers come with intrusion control, the connection can be hacked into by users local to the router. And for the technological newbie, they may not even realise their router is open to external connections. Without updating the router's firmware security on a regular basis, it will always remain a target for leeches, hackers and user's with malicious intent. Also, the further away from the wireless router a user is, the weaker the radio signal is, and the slower the connection speed becomes.
So what's the alternative? A wired router. This router is isolated from wireless connections, so you have no need to worry about security. Instead, the only connection option is through the use of an ethernet cable. A standard home router will typical only contain four ethernet hubs. Therefore, if you were hoping to host 253 users on your connection, you are bang out of luck.
The advantage to a wired ethernet connection is it's reliability. No matter the distance from the router, the ethernet cable will ensure a standard speed. Other electrical devices cannot effect the quality of the connection speed, unlike with a wireless router. A wired router is simplier to setup for the technological novice. You will have no worries about security and wep encryption.