A top-level domain (TLD), sometimes referred to as a top-level domain name (TLDN), is the last part of an Internet domain name; that is, the letters which follow the final dot of any domain name. In Computer networking, a domain name is a name given to a collection of network devices that belong to a domain which is an administrative space managed according For example, in the domain name www. example. com, the top-level domain is com (or COM, as domain names are not case-sensitive). Text sometimes exhibits case sensitivity; that is words can differ in meaning based on differing use of uppercase and lowercase letters Management of top-level domains is handled by the ICANN. ICANN (aɪkæn eye-can is the Internet Corporation for Assigned Names and Numbers.
The Internet Assigned Numbers Authority (IANA) currently classifies top-level domains into three types:
- country code top-level domains (ccTLD): Used by a country or a dependent territory. The Internet Assigned Numbers Authority (IANA is the entity that oversees global IP address allocation, DNS root zone management, media types A country In Political geography and International politics, a country is a Political division of a geographical entity A dependent territory dependent area or dependency is a territory that does not possess full political Independence or Sovereignty as a It is two letters long, for example .us for the United States. The United States of America —commonly referred to as the With some historical exceptions, the code for any territory is the same as its two-letter ISO 3166 code. ISO 3166 is a three-part Geographic coding standard for coding the names of countries and Dependent areas and the principal subdivisions
- generic top-level domains (gTLD): Used (at least in theory) by a particular class of organizations (for example, .com for commercial organizations). History The initial set of top-level domains defined by RFC 920 in October 1984 was a set of "general purpose domains" It is three or more letters long. Most gTLDs are available for use worldwide, but for historical reasons .mil (military) and .gov (governmental) are restricted to use by the respective U. The United States Armed Forces are the overall unified military forces of the United States The federal government of the United States is the central United States Governmental body established by the United States Constitution. S. authorities. gTLDs are subclassified into sponsored top-level domains (sTLD), e. A sponsored top-level domain ( sTLD) is one of the categories of Top-level domains (TLDs maintained by the Internet Assigned Numbers Authority (IANA for g. . aero, . coop and . museum, and unsponsored top-level domains (uTLD), e. History The initial set of top-level domains defined by RFC 920 in October 1984 was a set of "general purpose domains" g. . biz, . info, and . name.
- infrastructure top-level domains (iTLD): The top-level domain .arpa is the only confirmed one. .root has been known to exist without reason.
A full list of currently existing TLDs can be found at the list of Internet top-level domains. The following is a list of currently existing Internet Top-level domains (TLDs)
Contents |
Historical TLDs
A .nato was added in the late 1980s by the NIC for the use of NATO, who felt that none of the then existing TLDs adequately reflected their status as an international organization. The North Atlantic Treaty International Organization is a peer-reviewed Academic journal that covers the entire field of International affairs. Soon after this addition, however, the NIC created the .int TLD for the use of international organizations, and persuaded NATO to use nato. int instead. However, the nato TLD, although no longer used, was not deleted until July 1996.
Other historical TLDs are .cs for Czechoslovakia (now .cz for Czech Republic and .sk for Slovak Republic), and .zr for Zaire (now .cd for Democratic Republic of the Congo). Czechoslovakia may also refer to what is now the Czech Republic and Slovakia. The Czech Republic ( ˈt͡ʃɛskaː ˈrɛpuˌblɪka short form in Česko ˈt͡ʃɛskɔ also called Czechia, Slovakia (long form Slovak Republic; Slovak:, long form, is a Landlocked country in Central Europe with a population of over five million The Republic of Zaire (pronunciation; République du Zaïre was the name of the present Democratic Republic of the Congo between October 27, 1971 The Democratic Republic of the Congo (République démocratique du Congo often referred to as DR Congo, DRC or RDC, and formerly known or referred to In contrast to these, the TLD .su has remained in active use despite the demise of the Soviet Union that it represents, though .ru is most commonly used for Russian domains. The Union of Soviet Socialist Republics (USSR was a constitutionally Socialist state that existed in Eurasia from 1922 to 1991 Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending
Commercial use of country code TLDs
A number of the world's smallest countries have licensed their TLDs for world-wide commercial use. For example, Niue, a tiny island in the South Pacific Ocean, has licensed the .nu TLD and it is used various places around the world, for example in Denmark, the Netherlands and Sweden, where the word "nu" means "now". Niue (niːˈʔuːeɪ/ /ˈnjuːeɪ in English is an Island nation located in the South Pacific Ocean. The Pacific Ocean is the largest of the Earth 's Oceanic divisions The Kingdom of Denmark ( ˈd̥ænmɑɡ̊ (archaic ˈd̥anmɑːɡ̊ commonly known as Denmark, is a country in the Scandinavian region of northern Europe The Netherlands ( Dutch:, ˈnedərlɑnt is the European part of the Kingdom of the Netherlands, which consists of the Netherlands the Netherlands "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. Similarly, Tuvalu and the Federated States of Micronesia, other small islands in the South Pacific, have partnered with VeriSign and FSM Telecommunications respectively, to sell domain names using the .tv and .fm TLDs to television and radio stations. Tuvalu, formerly known as the Ellice Islands, is a Polynesian Island nation located in the Pacific Ocean midway between Hawaii and The Federated States of Micronesia is an Island nation located in the Pacific Ocean, north of Papua New Guinea. VeriSign Inc ( is an American company based in Mountain View California that operates a diverse array of network infrastructure including two of the Cocos (Keeling) Islands of Australia promoted the use of their .cc as "the next .com", which garnered popularity due to its relative cheapness compared to . For a topic outline on this subject see List of basic Australia topics. com registration at the time.
Pseudo-domains
In the past the Internet was just one of many wide-area computer networks. Wide Area Network ( WAN) is a Computer network that covers a broad area (i Computers not connected to the Internet, but connected to another network such as BITNET, CSNET or UUCP, could generally exchange e-mail with the Internet via e-mail gateways. BITNET was a cooperative US university network founded by IBM in 1979 under the aegis of Ira Fuchs at the City University of New York (CUNY CSNET (the "Computer Science Network" was funded by the U UUCP is an Abbreviation for Unix to Unix CoPy. The term generally refers to a suite of Computer programs and protocols allowing remote execution When used on the Internet, addresses on these networks were often placed under pseudo-domains such as .bitnet, .oz, .csnet, and .uucp; however these pseudo-domains implemented in mail server configurations such as sendmail.cf and were not real top-level domains and did not exist in DNS. Sendmail is a Mail transfer agent (MTA that supports many kinds of mail transfer and delivery including the overwhelmingly popular SMTP. The Domain Name System (DNS is a hierarchical naming system for computers services or any resource participating in the Internet.
Most of these networks have long since ceased to exist, and although UUCP still gets significant use in parts of the world where Internet infrastructure has not yet become well-established, it subsequently transitioned to using Internet domain names, so pseudo-domains now largely survive as historical relics. One notable exception is the 2007 emergence of SWIFTNet Mail, which uses the . The Society for Worldwide Interbank Financial Telecommunication ("SWIFT" operates a worldwide financial messaging swift pseudo-domain. [1]
The anonymity network Tor has a pseudo-domain onion, which can only be reached with a Tor client because it uses the Tor-protocol (onion routing) to reach the hidden service in order to protect the anonymity of the domain. Tor ( The Onion Router) is a Free software implementation of second-generation Onion routing – a system enabling its users to communicate anonymously Onion routing is a technique for anonymous communication over a Computer network.
.local deserves special mention as it is required by the Zeroconf protocol. Zeroconf, or Zero Configuration Networking, is a set of techniques that automatically create a usable IP network without configuration or special servers It is also used by many organizations internally, which will become a problem for those users as Zeroconf becomes more popular. Both . site and . internal have been suggested for private usage, but no consensus has yet emerged.
Reserved TLDs
RFC 2606 reserves the following four top-level domain names for various purposes, with the intention that these should never become actual TLDs in the global DNS:
- .example — reserved for use in examples
- .invalid — reserved for use in obviously invalid domain names
- .localhost — reserved to avoid conflict with the traditional use of localhost
- .test — reserved for use in tests
In 2007 eleven IDN test TLDs were created:[2]
- . The Domain Name System (DNS is a hierarchical naming system for computers services or any resource participating in the Internet. In Computer networking of Unix-like operating systems localhost (meaning "this computer" is the standard Hostname given to the address of the Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. An internationalized domain name ( xn--kgbechtv Arabic
- . xn--hgbk6aj7f53bba Persian
- . xn--0zwm56d Chinese, simplified
- . xn--g6w251d Chinese, traditional
- . xn--80akhbyknj4f Russian
- . xn--11b5bs3a9aj6g Hindi
- . xn--jxalpdlp Greek
- . xn--9t4b11yi5a Korean
- . xn--deba0ad Yiddish
- . xn--zckzah Japanese
- . xn--hlcj6aya9esc7a Tamil
Debated TLDs
- Further information: Proposed top-level domain
About the time that ICANN discussed and finally introduced[3] .aero, .biz, .coop, .info, .museum, .name, and .pro TLDs, site owners and USENET users argued that a similar TLD should be made available for adult and pornographic websites to settle the dispute of obscene content on the internet and the responsibility of service providers under the questionable Communications Decency Act of 1996. There are several proposed top-level domains which have not yet been submitted to or approved by ICANN, as of 2008 ICANN (aɪkæn eye-can is the Internet Corporation for Assigned Names and Numbers. Usenet, a Portmanteau of "user" and "network" is a world-wide distributed Internet discussion system The Communications Decency Act of 1996 ( CDA) was arguably the first attempt by the United States Congress to regulate pornographic material on the Several options were proposed including .xxx, . sex and . adult, but so far ICANN chose not to create them.
An older proposal[4] consisted of seven new gTLDs . arts, . firm, .info, . nom, . rec, . shop, and .web. Later .biz, .info, .museum, and .name covered most of these old proposals.
TLDs in alternative roots
- Further information: Alternative DNS root
ICANN's slow progress in creating new gTLDs, and the relatively high registration costs associated with several TLDs, contributed to the creation of alternate root servers with their own sets of TLDs. The Internet uses a Domain Name System (DNS root officially administered by the Internet Corporation for Assigned Names and Numbers (ICANN History The initial set of top-level domains defined by RFC 920 in October 1984 was a set of "general purpose domains" At times, browser plugins have been developed to allow access to some set of "alternative" domain names even when the normal DNS roots are otherwise used.
References
- ^ SWIFT - About SWIFT - Press room - SWIFTNet Mail now available
- ^ ICANN IDN wiki
- ^ InterNIC FAQs on New Top-Level Domains
- ^ (historical) gTLD MoU
- Addressing the World: National Identity and Internet Country Code Domains, edited by Erica Schlesinger Wass (Rowman & Littlefield, 2003, ISBN 0-7425-2810-3) [1], examines connections between cultures and their ccTLDs.
- Ruling the Root by Milton Mueller (MIT Press, 2001, ISBN 0-262-13412-8) [2], discusses TLDs and domain name policy more generally.
See also
External links
Dictionary
top-level domain
-noun
- (computing, internet) The last component of a domain name, such as .com, .edu, .gov, .net, .org, .mil or any of the newer generic top-level domains, or any of the ccTLDs. Abbreviated TLD.
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic