What is a domain name?

Internet servers are identified by a unique IP address (e.g. 132.185.132.204), but this is not easy to remember so a system called DNS allows us to associate a text string called a domain name (e.g. sitesystem.co.uk) with a server's IP address. A web address is used to locate HTML pages on a particular server (e.g. www.sitesystem.co.uk), and an email address (e.g. info@sltesystem.co.uk) points emails to mail accounts, often on the same server as the website.

The legalities surrounding domain names are complex, but in effect, domain names are leased and must have their ownership renewed every year or two. The main types of domain suffix in use by UK businesses are: 'com' (the worldwide suffix for 'commercial'); co.uk (the standard UK commercial suffix); 'org' (strictly speaking for use by non-profit organisations); and 'net' (for internet companies). Many other suffixes are in use, but people will rarely try to guess a domain name beyond 'com' or 'co.uk'.