What is a domain name?

All computers on the Internet have their own Internet Protocol (IP) address which consists of numbers. The domain name system connects unique domain names to the IP addresses so users do not have to remember a long string of numbers. Domain names are used in web addresses (http://www.nominet.org.uk)and in email addresses (firstname.lastname@nominet.org.uk) among other things.

Domain names consist of a varying number of segments. The part on the far right of a domain name is known as a top-level domain (TLD). For example, in the domain name nominet.org.uk the top level domain is .uk. The part to the left of the top level domain is known as the second-level domain (SLD).

Second level domain names

In the Domain Name System (DNS) hierarchy, a second-level domain (SLD) is a domain that is directly below a top-level domain (TLD). For example, in the domain name 'nominet.org.uk', the .uk is the top level, and the .org is the second level. SLDs commonly indicate the type of organisations that would register domains within them. For example, in .uk, the .org SLD is for organisations, .co is for companies and .me is for personal use. Find out more about the SLDs we manage.

Rules

Read the rules of registering a domain name and use of domain names within the .uk domain.

Legal information

Read the legal information relating to a domain name registration, including  information about the rules, contracts and data protection.