Before Broadband there was dial-up connection to the Internet, and before that dial-up between individual computers which could run bulletin boards and file sharing. Broadband is always on, unlike dial-up.
Home Broadband is the main focus of this website, though some of the providers offer Mobile Broadband as well. At home the Broadband is carried over the same wires as the telephone line, but uses a different frequency.
Broadband can be unlimited, in which case you can use as much bandwidth as the connection allows for as long as you want. This is becoming much more common in the competitive world of data connections. The Broadband can be limited and charged by amount of data downloaded in a given period, or by bandwidth available. The length of contract can also effect the cost per month.
A relatively recent distinction is between ADSL, which is a connection over the standard telephone network, and Fibre Broadband, which uses the new optical fibre network. Some Broadband Providers will also package it with telephone and TV.