.gov

.gov
Introduced 1985
TLD type Sponsored top-level domain
Status Active
Registry General Services Administration
Sponsor General Services Administration
Intended use Governmental entities
Actual use United States government; formerly only federal government but later expanded to include state and local government
Registration restrictions Must meet eligibility requirements and submit authorization letter
Structure Registrations at second level permitted
Documents RFC 920; RFC 1591; RFC 2146
Dispute policies None
Website dotgov.gov
DNSSEC yes

The domain name gov is a sponsored top-level domain (sTLD) in the Domain Name System of the Internet. The name is derived from government, indicating its restricted use by government entities in the United States. The gov domain is administered by the General Services Administration (GSA), an independent agency of the United States federal government.

The U.S. is the only country that has a government-specific top-level domain in addition to its country-code top-level domain. This is a result of the origins of the Internet as a U.S. federal government-sponsored research network (see ARPANET and National Science Foundation Network). Other countries typically delegate a second-level domain for this purpose, for example: .gc.ca is the second-level domain for the Government of Canada and all subdomains.

Some U.S. federal agencies use fed.us rather than gov. The Department of Defense and its subsidiary organizations use the mil sTLD. Some U.S. governmental entities use other domains, such as com domains by the United States Postal Service (which uses both usps.gov and usps.com for the same website, although it only advertises the com address), and the United States Army's recruitment website (goarmy.com, this trend is repeated at the recruitment websites of the other branches of the U.S. military).

All governments in the U.S. are allowed to apply for delegations in gov, such as atlantaga.gov for the city of Atlanta, loudoun.gov for the county of Loudoun, Virginia and georgia.gov for the U.S. state of Georgia. This was not always true; under an earlier policy, only federal agencies were allowed to use the domain, and agencies beneath cabinet level were required to use subdomains of their parent agency. There is a lack of consistency in addresses of state and local government sites, with some using gov, some us, some using both (the Commonwealth of Pennsylvania uses www.pa.gov, www.pennsylvania.gov and www.state.pa.us for the same web site) and still others in com, org or other TLDs.

Read more about .gov:  Availability, Authorization, Naming Conventions, Policy, States in GOV, New Zealand