Domain name

Domain name

In the <a href="/en/Internet" title="Internet" class="wl">Internet</a>, a domain name is a <a href="/en/String_(computer_science)" title="String (computer science)" class="wl">string</a> that identifies a realm of administrative autonomy, authority or control. Domain names are often used to identify services provided through the Internet, such as <a href="/en/Website" title="Website" class="wl">websites</a>, <a href="/en/Email" title="Email" class="wl">email</a> services and more. As of 2017, 330.6 million domain names had been registered.<a href="#cite_note-1" style="counter-reset: mw-Ref 1;">[1]</a> Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a <a href="/en/Network_domain" title="Network domain" class="wl">network domain</a> or an <a href="/en/Internet_Protocol" title="Internet Protocol" class="wl">Internet Protocol</a> (IP) resource, such as a personal computer used to access the Internet, or a server computer.

<div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none" about="#mwt1">Identification string in the Internet</div>
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Domain names are formed by the rules and procedures of the <a href="/en/Domain_Name_System" title="Domain Name System" class="wl">Domain Name System</a> (DNS). Any name registered in the DNS is a domain name. Domain names are organized in subordinate levels (subdomains) of the <a href="/en/DNS_root" title="DNS root" class="mw-redirect wl">DNS root</a> domain, which is nameless. The first-level set of domain names are the <a href="/en/Top-level_domain" title="Top-level domain" class="wl">top-level domains</a> (TLDs), including the <a href="/en/Generic_top-level_domain" title="Generic top-level domain" class="wl">generic top-level domains</a> (gTLDs), such as the prominent domains <a href="/en/.com" title=".com" class="wl">com</a>, <a href="/en/.info" title=".info" class="wl">info</a>, <a href="/en/.net" title=".net" class="wl">net</a>, <a href="/en/.edu" title=".edu" class="wl">edu</a>, and <a href="/en/.org" title=".org" class="wl">org</a>, and the <a href="/en/Country_code_top-level_domain" title="Country code top-level domain" class="wl">country code top-level domains</a> (ccTLDs). Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites.

The registration of a second- or third-level domain name is usually administered by a <a href="/en/Domain_name_registrar" title="Domain name registrar" class="wl">domain name registrar</a> who sell its services to the public. 

A <a href="/en/Fully_qualified_domain_name" title="Fully qualified domain name" class="wl">fully qualified domain name</a> (FQDN) is a domain name that is completely specified with all labels in the hierarchy of the DNS, having no parts omitted. Traditionally a FQDN ends in a dot (.) to denote the top of the DNS tree.<a href="#cite_note-2" style="counter-reset: mw-Ref 2;">[2]</a> Labels in the Domain Name System are <a href="/en/Case-insensitive" title="Case-insensitive" class="mw-redirect wl">case-insensitive</a>, and may therefore be written in any desired capitalization method, but most commonly domain names are written in lowercase in technical contexts.<a href="#cite_note-3" style="counter-reset: mw-Ref 3;">[3]</a>

In the Internet, a domain name is a string that identifies a realm of administrative autonomy, authority or control. Domain names are often used to identify services provided through the Internet, such as websites, email services and more. As of 2017, 330.6 million domain names had been registered. Domain names are used in various networking contexts and for application-specific naming and addressing purposes. In general, a domain name identifies a network domain or an Internet Protocol resource, such as a personal computer used to access the Internet, or a server computer. Domain names are formed by the rules and procedures of the Domain Name System . Any name registered in the DNS is a domain name. Domain names are organized in subordinate levels of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains , including the generic top-level domains , such as the prominent domains com, info, net, edu, and org, and the country code top-level domains . Below these top-level domains in the DNS hierarchy are the second-level and third-level domain names that are typically open for reservation by end-users who wish to connect local area networks to the Internet, create other publicly accessible Internet resources or run web sites. 