"third level domains, but not all registrants have to use them. Many ccTLDs have moved from compulsory third or fourth-level domain to the availability of registrations of second level domains. Among them are .us (April 2002), .mx (May 2009), .co (March 2010)., and .uk (June 2014). Domain name registry A domain name registry is a database of all domain names and the associated registrant information in the top level domains of the Domain Name System (DNS) of the Internet that allow third party entities to request administrative control of a domain name. Most registries operate on the top-level and second-level"
"of 211 countries in the world. The United States ranks #1 in the world with 7,000 Internet Service Providers (ISPs) according to the CIA. Internet top-level domain names specific to the U.S. include .us, .edu, .gov, .mil, .as (American Samoa), .gu (Guam), .mp (Northern Mariana Islands), .pr (Puerto Rico), and .vi (U.S. Virgin Islands). Many U.S.-based organizations and individuals also use generic top-level domains, such as .com, .net, .org, .name, etc. Access to the Internet can be divided into dial-up and broadband access. Around the start of the 21st century, most residential access was by dial-up, while access from businesses"
".gov The 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 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. Other countries typically delegate a second-level"
"its delegated localities to organizations that have a mailing address in that locality. .us .us is the Internet country code top-level domain (ccTLD) for the United States of America. It was established in 1985. Registrants of .us domains must be American citizens, residents, or organizations, or a foreign entity with a presence in the United States of America. Most registrants in the United States of America have registered for .com, .net, .org and other gTLDs, instead of .us, which has primarily been used by state and local governments despite any entity having the option of registering a .us domain. On"
".mil The domain name mil is the sponsored top-level domain (sTLD) in the Domain Name System of the Internet for the United States Department of Defense and its subsidiary or affiliated organizations. The name is derived from ""military"". It was one of the first top-level domains, created in January 1985. The United States is the only country that has a top-level domain for its military, a legacy of the United States' military role in the creation of the Internet. Other countries often use second-level domains for this purpose, e.g., ""mod.uk"" for the United Kingdom's Ministry of Defence. Canada uses ""norad.mil"""
".us .us is the Internet country code top-level domain (ccTLD) for the United States of America. It was established in 1985. Registrants of .us domains must be American citizens, residents, or organizations, or a foreign entity with a presence in the United States of America. Most registrants in the United States of America have registered for .com, .net, .org and other gTLDs, instead of .us, which has primarily been used by state and local governments despite any entity having the option of registering a .us domain. On February 15, 1985, .us was created as the Internet's first ccTLD. Its original"
"use the top-level pseudo-domain home for local DNS resolution of routers, modems and gateways. 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. 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 label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is com. Responsibility for management of most top-level domains is delegated to"
"value."" Generic top-level domain Generic top-level domains (gTLDs) are one of the categories of top-level domains (TLDs) maintained by the Internet Assigned Numbers Authority (IANA) for use in the Domain Name System of the Internet. A top-level domain is the last level of every fully qualified domain name. They are called generic for historic reasons; initially, they were contrasted with country-specific TLDs in RFC 920. The core group of generic top-level domains consists of the com, info, net, and org domains. In addition, the domains biz, name, and pro are also considered ""generic""; however, these are designated as ""restricted"", because"
"top-level domains to provide a platform for advertising, most notably VeriSign for .com and .net with its (now removed) Site Finder system. The .museum TLD also had a wildcard record which has now been removed. , top-level domains using a wildcard A record (other than 127.0.53.53) are .fm, .la, .ph, .pw, .vg and .ws. The internationalized TLDs .中国 (.xn--fiqs8s or .xn--fiqz9s for ""China"") and .გე (.xn--node for the Georgian letters for the Georgian country code ""GE"") also have wildcard A records. The codice_1 wildcard resolves to codice_2 (flagged by Chrome as unsafe), and the codice_3 wildcard resolves to a website"
"was divided into two main groups of domains. The country code top-level domains (ccTLD) were primarily based on the two-character territory codes of ISO-3166 country abbreviations. In addition, a group of seven generic top-level domains (gTLD) was implemented which represented a set of categories of names and multi-organizations. These were the domains gov, edu, com, mil, org, net, and int. During the growth of the Internet, it became desirable to create additional generic top-level domains. As of October 2009, 21 generic top-level domains and 250 two-letter country-code top-level domains existed. In addition, the ARPA domain serves technical purposes in the"
"Internet can be regarded as ending with this empty string for the root domain, and therefore ending in a full stop character (the label delimiter), e.g., ""www.example.com."". This is generally implied rather than explicit, as modern DNS software does not actually require that the terminating dot be included when attempting to translate a domain name to an IP address. The root domain contains all top-level domains of the Internet. , it contains 1058 TLDs, including 730 generic top-level domains (gTLDs) and 301 country code top-level domains (ccTLDs) in the root domain. In addition, the ARPA domain is used for technical"
"names for the countries of Egypt, Saudi Arabia, and the United Arab Emirates. By May 2010, 21 countries had submitted applications to ICANN, representing 11 scripts. The domain arpa was the first Internet top-level domain. It was intended to be used only temporarily, aiding in the transition of traditional ARPANET host names to the domain name system. However, after it had been used for reverse DNS lookup, it was found impractical to retire it, and is used today exclusively for Internet infrastructure purposes such as in-addr.arpa for IPv4 and ip6.arpa for IPv6 reverse DNS resolution, uri.arpa and urn.arpa for the"
"via the Internet. In 2017, 330.6 million domain names had been registered. Domain names are organized in subordinate levels (subdomains) of the DNS root domain, which is nameless. The first-level set of domain names are the top-level domains (TLDs), including the generic top-level domains (gTLDs), such as the prominent domains com, info, net, edu, and org, and the country code top-level domains (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"
"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. 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 label of a fully qualified domain name. For example, in the domain name www.example.com, the top-level domain is com. Responsibility for management of most top-level domains is delegated to specific organizations by the Internet Corporation for Assigned Names and Numbers (ICANN), which operates"
"Pseudo-top-level domain A pseudo-top-level domain is a label or name for a computer network that is not participating in the world-wide official Domain Name System and may not even participate in the Internet, but may use a similar domain name hierarchy. Historically the best known large networks in this group were .bitnet, .csnet, .oz, and .uucp, for which many Internet mail forwarders provided connectivity. In addition, newer networks like .exit, .i2p, may be included. (Newest draft of the proposal expired on July 28, 2015 without becoming a standard.) Some domains such as .onion may later become officially recognised. Although these"
"each U.S. state, federal territory, and the District of Columbia. Each domain corresponds to a USPS abbreviation. For example, .ny.us is reserved for websites affiliated with New York, while .va.us is for those affiliated with Virginia. Second-level domains are also reserved for five U.S. territories: .as.us for American Samoa, .gu.us for Guam, .mp.us for the Northern Mariana Islands, .pr.us for Puerto Rico, and .vi.us for the U.S. Virgin Islands. However, these domains go unused because each territory has its own ccTLD per ISO 3166-1 alpha-2: respectively, .as, .gu, .mp, .pr, and .vi. A state's main government portal is usually found"
".arpa The domain name arpa is a top-level domain (TLD) in the Domain Name System of the Internet. It is used exclusively for technical infrastructure purposes. While the name was originally the acronym for the Advanced Research Projects Agency (ARPA), the funding organization in the United States that developed one of the precursors of the Internet (ARPANET), it now stands for Address and Routing Parameter Area. The top-level domain was the first domain installed in the Domain Name System (DNS). It was originally intended to be a temporary domain to facilitate the transition of the ARPANET host naming conventions and"
"Generic top-level domain Generic top-level domains (gTLDs) are one of the categories of top-level domains (TLDs) maintained by the Internet Assigned Numbers Authority (IANA) for use in the Domain Name System of the Internet. A top-level domain is the last level of every fully qualified domain name. They are called generic for historic reasons; initially, they were contrasted with country-specific TLDs in RFC 920. The core group of generic top-level domains consists of the com, info, net, and org domains. In addition, the domains biz, name, and pro are also considered ""generic""; however, these are designated as ""restricted"", because registrations"
"the Internet when the Domain Name System was implemented in January 1985, the others being edu, gov, mil, net, org, and arpa. It has grown into the largest top-level domain. The domain com was one of the first set of top-level domains when the Domain Name System was first implemented for use on the Internet in January 1985. The domain was administered by the U.S. Department of Defense (DoD), however the department contracted the domain maintenance to SRI International. SRI created DDN-NIC, also known as SRI-NIC, or simply ""the NIC"" (Network Information Center), then accessible online with the domain name"
".com The domain name com is a top-level domain (TLD) in the Domain Name System of the Internet. Its name is derived from the word ""commercial"", indicating its original intended purpose for domains registered by commercial organizations. Later, the domain opened for general purposes. The domain was originally administered by the United States Department of Defense, but is today operated by Verisign, and remains under ultimate jurisdiction of U.S. law. Verisign Registrations in the .com domain are processed via registrars accredited by ICANN. The registry accepts internationalized domain names. The domain was one of the original top-level domains (TLDs) in"
"at the third-level domain state.<state>.us, which is reserved for this purpose. However, some state administrations prefer .gov domains: for example, California's government portal is located at both and , while redirects to Massachusetts's portal at . Fully spelled-out names of states are also reserved under .us, so the State of Ohio's website was at one point available at in addition to the usual , with the former remaining as a redirect. Other than for state governments, no third-level domain registrations are permitted under state or territory second-level domains. A few additional names are reserved at the second level for government"
"or in local testing scenarios. The top-level domain is explicitly intended to be used in documentation or other technical writing, when domain names are presented as examples in usage or presentation of concepts of the Domain Name System or the Internet. .example The name example is reserved by the Internet Engineering Task Force (IETF) in RFC 2606 (June 1999) as a domain name that may not be installed as a top-level domain in the Domain Name System (DNS) of the Internet. In 1999, the Internet Engineering Task Force reserved the DNS labels , , , and so that they may"
"part of a general attempt to improve the efficiency of U.S. governmental Web usage by weeding out unnecessary, redundant, outdated, or wasteful sites. Since May 2012, the Federal Executive Branch has a policy of registering no new second-level domains for its agencies, except on a case-by-case basis. Agencies are also prohibited from using other top-level domains such as .org and .com. ""Federal Agency domains"" were also deleted on August 26, 2014. , all states, the District of Columbia, and all territories except for the Northern Mariana Islands have operational domains in ""gov"": .gov The domain name gov is a sponsored"
"networks or domain names have no official status, some are generally regarded as having been unofficially grandfathered, and are unlikely ever to be allocated as top-level domains. Pseudo-top-level domain A pseudo-top-level domain is a label or name for a computer network that is not participating in the world-wide official Domain Name System and may not even participate in the Internet, but may use a similar domain name hierarchy. Historically the best known large networks in this group were .bitnet, .csnet, .oz, and .uucp, for which many Internet mail forwarders provided connectivity. In addition, newer networks like .exit, .i2p, may be"
"customers right to those products."" In agreement, Nick Wood, Managing Director of Valideus, suggested ""Your own gTLD demonstrates confidence and vision and may accelerate your brand and its value. An internet address at the Top Level is far better than registration at the 'low rent' Second Level."" However, some companies, like Pepsi, ruled out a branded gTLD. Unrestricted generic top-level domains are those domains that are available for registrations by any person or organization for any use. The prominent gTLDs in this group are com, net, org, and info. However, info was the only one of these, and the first,"
"years, making the new-domain registration fee US$100. In 1997 the United States Department of Commerce assumed authority over all generic TLDs. It is currently operated by VeriSign, which had acquired Network Solutions. VeriSign later spun off Network Solutions' non-registry functions into a separate company which continues as a registrar. In the English language the domain is often spelled with a leading period and commonly pronounced as ""dot-com"", and has entered common parlance this way. Although com domains were originally intended to designate commercial entities (others such as government agencies or educational institutions have different top-level domains assigned to them), there"
"if it should ever become available in the future. Single-letter second-level domain Single-letter second-level domains are domain names in which the second-level domain consists of only one letter, such as x.com. In 1993, the Internet Assigned Numbers Authority (IANA) explicitly reserved all single-letter and single-digit second-level domain names in the top-level domains com, net, and org, and grandfathered those that had already been assigned. In December 2005, ICANN considered auctioning these domains. On December 1, 1993, the Internet Assigned Numbers Authority (IANA) explicitly reserved the remaining single-letter and single-digit domain names. The few domains that were already assigned were grandfathered"
"Internet in the United States The Internet in the United States grew out of the ARPANET, a network sponsored by the Advanced Research Projects Agency of the U.S. Department of Defense during the 1960s. The Internet in the United States in turn provided the foundation for the worldwide Internet of today. Internet access in the United States is largely provided by the private sector and is available in a variety of forms, using a variety of technologies, at a wide range of speeds and costs. In 2015, 97.5% of Americans were using the Internet, which ranks the U.S. 4th out"
"of use and administration. The term ""domain"" is used in the business functions of the entity assigned to it and the term ""zone"" is usually used for configuration of DNS services. The top-level domain arpa serves as a delegation zone for various technical infrastructure aspects of DNS and the Internet, and does not implement the registration and delegation system of the country and generic domains. The name ""arpa"" is a remnant of the ARPANET, one of the predecessor stages of the Internet. Intended as a transitional aid to the DNS system, deleting the domain arpa was later found to be"
"Alternative DNS root The 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. These alternative domain name systems operate their own root nameservers and commonly administer their own specific name spaces consisting of"
"group of domains is therefore commonly known as country-code top-level domains (ccTLD). Since 2009, countries with non–Latin-based scripts may apply for internationalized country code top-level domain names, which are displayed in end-user applications in their language-native script or alphabet, but use a Punycode-translated ASCII domain name in the Domain Name System. Generic top-level domains (formerly Categories) initially consisted of gov, edu, com, mil, org, and net. More generic TLDs have been added, such as info. The authoritative list of currently existing TLDs in the root zone is published at the IANA website at https://www.iana.org/domains/root/db/. An internationalized country code top-level domain"
"Public Suffix List The Public Suffix List is a catalog of certain Internet domain names. The term is also known by the form effective top-level domain (eTLD). The Mozilla Foundation maintains suffix list for the security and privacy policies of its Firefox web browser, though it is available for other uses under the Mozilla Public License (MPL). The list is used by Mozilla browsers (Firefox), by Google in Chrome and Chromium projects on certain platforms,) and by Opera. Future versions of Internet Explorer will also use the list. According to Mozilla, While ""com"", ""uk"", and ""us"" are top-level domains (TLDs),"
"as com or org) used on the second level. The second level domain names are intended to have Cyrillic characters only, but some have Latin characters or digits instead. For the third level names, it is fairly common that ""www"" (Latin characters) are used, but most main company addresses don't use any third level name. .рф The domain name .рф (romanized as .rf; abbreviation of ) is the Cyrillic country code top-level domain for the Russian Federation, in the Domain Name System of the Internet. In the Domain Name System it has the ASCII DNS name . The domain accepts"