Concept
.ac
Related concepts (4)
.sh
.sh is the Internet country code top-level domain (ccTLD) for the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha, although it is primarily used in Saint Helena (Ascension Island has its own ccTLD, .ac). Registrations of internationalized domain names are also accepted. On 22 February 2010 the ISO 3166-1 code for Saint Helena, Ascension and Tristan da Cunha changed to reflect the SH used for the ccTLD. There are seven second level domains: co.sh – commercial entities com.
Country code top-level domain
A country code top-level domain (ccTLD) is an Internet top-level domain generally used or reserved for a country, sovereign state, or dependent territory identified with a country code. All ASCII ccTLD identifiers are two letters long, and all two-letter top-level domains are ccTLDs. In 2018, the Internet Assigned Numbers Authority (IANA) began implementing internationalized country code top-level domains, consisting of language-native characters when displayed in an end-user application.
.uk
.uk is the Internet country code top-level domain (ccTLD) for the United Kingdom. It was first registered in July 1985, seven months after the original generic top-level domains such as .com and the first country code after .us. it is the fifth most popular top-level domain worldwide (after .com, .cn, .de and .net), with over 10 million registrations. uk has used OpenDNSSEC since March 2010. Internet in the United Kingdom#History and Nominet UK#History In October 1984, RFC 920 set out the creation of ccTLDs using country codes derived from the corresponding two-letter code in the ISO 3166-1 list.
Top-level domain
A top-level domain (TLD) is one of the domains at the highest level in the hierarchical Domain Name System of the Internet after the root domain. The top-level domain names are installed in the root zone of the name space. For all domains in lower levels, it is the last part of the domain name, that is, the last non empty label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is .com.