.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.
Hosts (file)The hosts is an operating system file that maps hostnames to IP addresses. It is a plain text file. Originally a file named HOSTS.TXT was manually maintained and made available via file sharing by Stanford Research Institute for the ARPANET membership, containing the hostnames and address of hosts as contributed for inclusion by member organizations. The Domain Name System, first described in 1983 and implemented in 1984, automated the publication process and provided instantaneous and dynamic hostname resolution in the rapidly growing network.
Example.comThe domain names example.com, example.net and example.org are second-level domain names in the Domain Name System of the Internet. They are reserved by the Internet Assigned Numbers Authority (IANA) at the direction of the Internet Engineering Task Force (IETF) as special-use domain names for documentation purposes. The domain names are used widely in books, tutorials, sample network configurations, and generally as examples for the use of domain names.
.info.info is a generic top-level domain (gTLD) in the Domain Name System (DNS) of the Internet. The name is derived from information, although registration requirements do not prescribe any particular purpose. The TLD info followed ICANN's highly publicized announcement, in late 2000, of a phased release of seven new generic top-level domains. The event was the first addition of major gTLDs since the Domain Name System was developed in the 1980s. The seven new gTLDs, selected from over 180 proposals, were meant in part to take the pressure off the domain.
URLA Uniform Resource Locator (URL), colloquially termed a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifier (URI), although many people use the two terms interchangeably. URLs occur most commonly to reference web pages (HTTP/HTTPS) but are also used for file transfer (), email (mailto), database access (JDBC), and many other applications.
Uniform Resource IdentifierA Uniform Resource Identifier (URI) is a unique sequence of characters that identifies a logical or physical resource used by web technologies. URIs may be used to identify anything, including real-world objects, such as people and places, concepts, or information resources such as web pages and books. Some URIs provide a means of locating and retrieving information resources on a network (either on the Internet or on another private network, such as a computer filesystem or an Intranet); these are Uniform Resource Locators (URLs).
Email addressAn email address identifies an email box to which messages are delivered. While early messaging systems used a variety of formats for addressing, today, email addresses follow a set of specific rules originally standardized by the Internet Engineering Task Force (IETF) in the 1980s, and updated by . The term email address in this article refers to just the addr-spec in Section 3.4 of RFC 5322. The RFC defines address more broadly as either a mailbox or group.
.govThe domain name gov is a sponsored top-level domain (sTLD) in the Domain Name System of the Internet. The name is derived from the word government, indicating its restricted use by government entities. The TLD is administered by the Cybersecurity and Infrastructure Security Agency (CISA), a component of the United States Department of Homeland Security. gov is one of the original six top-level domains, defined in RFC 920. Though "originally intended for any kind of government office or agency", only U.S.
Alternative DNS rootThe Internet uses the Domain Name System (DNS) to associate numeric computer IP addresses with human-readable names. The top level of the domain name hierarchy, the DNS root, contains the top-level domains that appear as the suffixes of all Internet domain names. The most widely used (and first) DNS root is administered by the Internet Corporation for Assigned Names and Numbers (ICANN). In addition, several organizations operate alternative DNS roots, often referred to as alt roots.
.intThe domain name int is a sponsored top-level domain (sTLD) in the Domain Name System of the Internet. Its name is derived from the word international, characterizing its use for international organizations and treaty-related purposes. The first use of this domain was by NATO, which had previously been assigned the top-level domain .nato. According to Internet Assigned Numbers Authority (IANA) policy, based on RFC 1591, the sTLD int is reserved for international treaty-based organizations, United Nations agencies, and organizations or entities having observer status at the UN.