The domain name is an integral part of every website and choosing the right name can be more important than the business name. The domain is the first part of every URL in the address bar of the browser - so, for example, 'rocketlawyer.co.uk'. There are two elements to each domain name: the name itself (ie 'rocketlawyer') and the suffix (ie '.co.uk'). The suffix is often used to indicate the geographical location or nature of the business.
Anyone can register a domain name which has not already been registered, by paying a domain name registration company (eg www.123-reg.co.uk or www.1and1.co.uk) to register it with the relevant domain name authority (eg for domains which use a '.uk' suffix this is Nominet). Domain names are normally registered for one or two years and renewed before the registration period expires. If they are not renewed, they become available for registration by a different business or individual.
If a domain name has already been registered, it can be purchased privately and then transferred across to the purchaser. However, this is generally more expensive, particularly as many businesses register attractive domains in order to make a profit by selling them on (see cybersquatting below).