Domain Name System

<table><tbody><tr><td>Internet history timeline</td></tr><tr><td>Early research and development:<ul><li>1960–1964: <a href="/facts/RAND/zArfRxf9">RAND</a> networking concepts developed</li><li>1962–1964: <a href="/facts/DARPA/Uf9sarhT">ARPA</a> networking ideas</li><li>1965 (1965): <a href="/facts/NPL_network/JWc0pxUu">NPL network</a> concepts conceived</li><li>1966 (1966): <a href="/facts/Merit_Network/1qL7oxsn">Merit Network</a> founded</li><li>1967 (1967): <a href="/facts/ARPANET/LyMGWurJ">ARPANET</a> planning begins</li><li>1967 (1967): <a href="/facts/Symposium_on_Operating_Systems_Principles/VhguUHDg">Symposium on Operating Systems Principles</a></li><li>1969 (1969): NPL followed by the ARPANET carry their first packets</li><li>1970 (1970): <a href="/facts/InterNIC/s7DoYDR1">Network Information Center</a> (NIC)</li><li>1971 (1971): <a href="/facts/Tymnet/wFM59Gtb">Tymnet</a> switched-circuit network</li><li>1972 (1972): Merit Network's packet-switched network operational</li><li>1972 (1972): <a href="/facts/Internet_Assigned_Numbers_Authority/b6MlP6zQ">Internet Assigned Numbers Authority</a> (IANA) established</li><li>1973 (1973): <a href="/facts/CYCLADES/kJX66P6D">CYCLADES</a> network demonstrated</li><li>1973 (1973): <a href="/facts/PARC_Universal_Packet/ub0fExbh">PARC Universal Packet</a> development begins</li><li>1974 (1974): <a href="/facts/Transmission_Control_Program/Qq6VeEal">Transmission Control Program</a> specification published</li><li>1975 (1975): <a href="/facts/Telenet/VCgNaKux">Telenet</a> commercial packet-switched network</li><li>1976 (1976): <a href="/facts/X.25/yaGPqw2Y">X.25</a> protocol approved and deployed on <a href="/facts/Public_data_network/sMYs1t3f">public data networks</a></li><li>1978 (1978): <a href="/facts/Minitel/bTmoGeyh">Minitel</a> introduced</li><li>1979 (1979): <a href="/facts/Internet_Architecture_Board/JV2M6FNP">Internet Activities Board</a> (IAB)</li><li>1980 (1980): <a href="/facts/Usenet/lYJWFBR6">USENET</a> news using <a href="/facts/UUCP/dQ055F7b">UUCP</a></li><li>1980 (1980): <a href="/facts/Ethernet/nMfhU8tU">Ethernet</a> standard introduced</li><li>1981 (1981): <a href="/facts/BITNET/oVg6qRYp">BITNET</a> established</li></ul>Merging the networks and creating the Internet:<ul><li>1981 (1981): <a href="/facts/CSNET/alJ5aBQq">Computer Science Network</a> (CSNET)</li><li>1982 (1982): <a href="/facts/Internet_protocol_suite/KNkxtSpw">TCP/IP</a> protocol suite formalized</li><li>1982 (1982): <a href="/facts/Simple_Mail_Transfer_Protocol/TeCRKDpJ">Simple Mail Transfer Protocol</a> (SMTP)</li><li>1983 (1983): Domain Name System (DNS)</li><li>1983 (1983): <a href="/facts/MILNET/GGE4YIjI">MILNET</a> split off from ARPANET</li><li>1984 (1984): <a href="/facts/OSI_model/oxN9Xhjz">OSI Reference Model</a> released</li><li>1985 (1985): <a href="/facts/Domain_names/FDLD2m5G">First .COM domain name registered</a></li><li>1986 (1986): <a href="/facts/National_Science_Foundation_Network/b95QF5hR">NSFNET</a> with 56 kbit/s links</li><li>1986 (1986): <a href="/facts/Internet_Engineering_Task_Force/tIcCsFhX">Internet Engineering Task Force</a> (IETF)</li><li>1987 (1987): <a href="/facts/UUNET/ExCXPTcE">UUNET</a> founded</li><li>1988 (1988): <a href="/facts/National_Science_Foundation_Network/b95QF5hR">NSFNET</a> upgraded to 1.5 Mbit/s (T1)</li><li>1988 (1988): <a href="/facts/Morris_worm/moqgLa5t">Morris worm</a></li><li>1988 (1988): Complete <a href="/facts/Internet_protocol_suite/KNkxtSpw">Internet protocol suite</a></li><li>1989 (1989): <a href="/facts/Border_Gateway_Protocol/XfYgBzW3">Border Gateway Protocol</a> (BGP)</li><li>1989 (1989): <a href="/facts/PSINet/kp4KMV4Y">PSINet</a> founded, allows commercial traffic</li><li>1989 (1989): <a href="/facts/Federal_Internet_Exchange/yWKJnNXR">Federal Internet Exchanges (FIX East|FIXes)</a></li><li>1990 (1990): <a href="/facts/Government_Open_Systems_Interconnection_Profile/apFGyLp7">GOSIP</a> (without <a href="/facts/Internet_protocol_suite/KNkxtSpw">TCP/IP</a>)</li><li>1990 (1990): ARPANET decommissioned</li><li>1990 (1990): <a href="/facts/Advanced_Network_and_Services/2hyQa3uF">Advanced Network and Services</a> (ANS)</li><li>1990 (1990): <a href="/facts/UUNET/ExCXPTcE">UUNET/Alternet</a> allows commercial traffic</li><li>1990 (1990): <a href="/facts/Archie_(search_engine)/8EjLUsfL">Archie search engine</a></li><li>1991 (1991): <a href="/facts/Wide_area_information_server/eEaUzhJk">Wide area information server</a> (WAIS)</li><li>1991 (1991): <a href="/facts/Gopher_(protocol)/G2bpDRQJ">Gopher</a></li><li>1991 (1991): <a href="/facts/Commercial_Internet_eXchange/q3lVr6B7">Commercial Internet eXchange</a> (CIX)</li><li>1991 (1991): <a href="/facts/Advanced_Network_and_Services/2hyQa3uF">ANS CO+RE</a> allows commercial traffic</li><li>1991 (1991): <a href="/facts/World_Wide_Web/wvnTrWFq">World Wide Web</a> (WWW)</li><li>1992 (1992): <a href="/facts/National_Science_Foundation_Network/b95QF5hR">NSFNET</a> upgraded to 45 Mbit/s (T3)</li><li>1992 (1992): <a href="/facts/Internet_Society/scIaot5x">Internet Society</a> (ISOC) established</li><li>1993 (1993): <a href="/facts/Classless_Inter-Domain_Routing/YU0SEmfp">Classless Inter-Domain Routing</a> (CIDR)</li><li>1993 (1993): <a href="/facts/InterNIC/s7DoYDR1">InterNIC</a> established</li><li>1993 (1993): <a href="/facts/AOL/MAbT38QS">AOL</a> added <a href="/facts/Usenet/lYJWFBR6">USENET</a> access</li><li>1993 (1993): <a href="/facts/NCSA_Mosaic/qrA52r1E">Mosaic web browser</a> released</li><li>1994 (1994): <a href="/facts/Search_engine/SRntsbz2">Full text web search engines</a></li><li>1994 (1994): <a href="/facts/North_American_Network_Operators%27_Group/kMJqx1uf">North American Network Operators' Group</a> (NANOG) established</li></ul>Commercialization, privatization, broader access leads to the modern Internet:<ul><li>1995 (1995): New Internet architecture with commercial <a href="/facts/Internet_service_provider/dUacAxef">ISPs</a> connected at <a href="/facts/Network_Access_Point/slyWwUdH">NAPs</a></li><li>1995 (1995): <a href="/facts/National_Science_Foundation_Network/b95QF5hR">NSFNET</a> decommissioned</li><li>1995 (1995): <a href="/facts/GOSIP/apFGyLp7">GOSIP</a> updated to allow <a href="/facts/Internet_protocol_suite/KNkxtSpw">TCP/IP</a></li><li>1995 (1995): <a href="/facts/Very_high-speed_Backbone_Network_Service/t2tXNNJF">very high-speed Backbone Network Service (vBNS)</a></li><li>1995 (1995): <a href="/facts/IPv6/d4dg7kIL">IPv6</a> proposed</li><li>1996 (1996): <a href="/facts/AOL/MAbT38QS">AOL</a> changes pricing model from hourly to monthly</li><li>1998 (1998): <a href="/facts/ICANN/2EHgcUU1">Internet Corporation for Assigned Names and Numbers (ICANN)</a></li><li>1999 (1999): <a href="/facts/IEEE_802.11/ryEGu6Vq">IEEE 802.11b</a> wireless networking</li><li>1999 (1999): <a href="/facts/Internet2/APYDGudp">Internet2</a>/<a href="/facts/Abilene_Network/njAvcCxy">Abilene Network</a></li><li>1999 (1999): <a href="/facts/VBNS/t2tXNNJF">vBNS+</a> allows broader access</li><li>2000 (2000): <a href="/facts/Dot-com_bubble/dCFWQt0s">Dot-com bubble</a> bursts</li><li>2001 (2001): <a href="/facts/Top-level_domain/azjpPu2M">New top-level domain names activated</a></li><li>2001 (2001): <a href="/facts/Code_Red_(computer_worm)/FIpF7P8R">Code Red I</a>, <a href="/facts/Code_Red_II/JaIzccPA">Code Red II</a>, and <a href="/facts/Nimda/0JhyJeHK">Nimda</a> worms</li><li>2003 (2003): <a href="/facts/World_Summit_on_the_Information_Society/YB1uwGD0">UN World Summit on the Information Society (WSIS) phase I</a></li></ul><ul><li>2003 (2003): <a href="/facts/National_LambdaRail/CEYEVmcT">National LambdaRail</a> founded</li><li>2004 (2004): <a href="/facts/Working_Group_on_Internet_Governance/nSkgQ5Yv">UN Working Group on Internet Governance (WGIG)</a></li><li>2005 (2005): <a href="/facts/World_Summit_on_the_Information_Society/YB1uwGD0">UN WSIS phase II</a></li><li>2006 (2006): <a href="/facts/Internet_Governance_Forum/CV6emQNr">First meeting of the Internet Governance Forum</a></li><li>2010 (2010): <a href="/facts/Top-level_domain/azjpPu2M">First internationalized country code top-level domains</a> registered</li><li>2012 (2012): <a href="/facts/Generic_top-level_domain/X0sNABPE">ICANN begins accepting applications for new generic top-level domain names</a></li><li>2013 (2013): <a href="/facts/Montevideo_Statement_on_the_Future_of_Internet_Cooperation/1AGRS70j">Montevideo Statement on the Future of Internet Cooperation</a></li><li>2014 (2014): <a href="/facts/NetMundial_Initiative/xQdRq2r5">NetMundial international Internet governance proposal</a></li><li>2016 (2016): <a href="/facts/ICANN/2EHgcUU1">ICANN</a> contract with U.S. Dept. of Commerce ends, <a href="/facts/Internet_Assigned_Numbers_Authority/b6MlP6zQ">IANA</a> oversight passes to the global Internet community on October 1st</li></ul>Examples of Internet services:<ul><li>1989 (1989): <a href="/facts/AOL/MAbT38QS">AOL</a> dial-up service provider, email, instant messaging, and web browser</li><li>1990 (1990): <a href="/facts/IMDb/uWrqVYVy">IMDb</a> Internet movie database</li><li>1994 (1994): <a href="/facts/Yahoo/nKhTaV3M">Yahoo!</a> web directory</li><li>1995 (1995): <a href="/facts/Amazon_(company)/YzUTUVE8">Amazon</a> online retailer</li><li>1995 (1995): <a href="/facts/EBay/bDswVAKB">eBay</a> online auction and shopping</li><li>1995 (1995): <a href="/facts/Craigslist/sru3Dv3W">Craigslist</a> classified advertisements</li><li>1995 (1995): <a href="/facts/AltaVista/X0C5ts5p">AltaVista</a> search engine</li><li>1996 (1996): <a href="/facts/Outlook.com/I4sund79">Outlook (formerly Hotmail)</a> free web-based e-mail</li><li>1996 (1996): <a href="/facts/Baidu/VgAx7Pfu">RankDex</a> search engine</li><li>1997 (1997): <a href="/facts/Google_Search/LFnCogKt">Google Search</a></li><li>1997 (1997): <a href="/facts/Babel_Fish_(website)/g8d8G0nN">Babel Fish</a> automatic translation</li><li>1998 (1998): <a href="/facts/Yahoo_Groups/Xe4MwHFk">Yahoo Groups (formerly Yahoo! Clubs)</a></li><li>1998 (1998): <a href="/facts/PayPal/tlShukIa">PayPal</a> Internet payment system</li><li>1998 (1998): <a href="/facts/Rotten_Tomatoes/rLs7ktSY">Rotten Tomatoes</a> review aggregator</li><li>1999 (1999): <a href="/facts/2channel/9fKR8y13">2ch</a> Anonymous textboard</li><li>1999 (1999): <a href="/facts/I-mode/pLNzMYkP">i-mode</a> mobile internet service</li><li>1999 (1999): <a href="/facts/Napster/49fjWRT7">Napster</a> peer-to-peer file sharing</li><li>2000 (2000): <a href="/facts/Baidu/VgAx7Pfu">Baidu</a> search engine</li><li>2001 (2001): <a href="/facts/Futaba_Channel/szefe1jK">2chan</a> Anonymous imageboard</li><li>2001 (2001): <a href="/facts/BitTorrent/HP9ChWWW">BitTorrent</a> peer-to-peer file sharing</li><li>2001 (2001): <a href="/facts/Wikipedia/KDRNKWnc">Wikipedia</a>, the free encyclopedia</li><li>2003 (2003): <a href="/facts/LinkedIn/Iq2IcNMt">LinkedIn</a> business networking</li><li>2003 (2003): <a href="/facts/Myspace/dES860Ro">Myspace</a> social networking site</li><li>2003 (2003): <a href="/facts/Skype/qdKbuh23">Skype</a> Internet voice calls</li><li>2003 (2003): <a href="/facts/ITunes_Store/c3XFlT3q">iTunes Store</a></li><li>2003 (2003): <a href="/facts/4chan/eSLuYvUN">4chan</a> Anonymous imageboard</li><li>2003 (2003): <a href="/facts/The_Pirate_Bay/V8jQU7eP">The Pirate Bay</a>, <a href="/facts/Torrent_file/j0SwIJrW">torrent file</a> host</li><li>2004 (2004): <a href="/facts/Facebook/0IhXFR6u">Facebook</a> social networking site</li><li>2004 (2004): <a href="/facts/Podcast/arkeh0YV">Podcast</a> media file series</li><li>2004 (2004): <a href="/facts/Flickr/BvB6ubLr">Flickr</a> image hosting</li><li>2005 (2005): <a href="/facts/YouTube/db276jst">YouTube</a> video sharing</li><li>2005 (2005): <a href="/facts/Reddit/PAJjm63I">Reddit</a> link voting</li><li>2005 (2005): <a href="/facts/Google_Earth/jjJmIjmb">Google Earth</a> virtual globe</li><li>2006 (2006): <a href="/facts/Twitter/VWwDNGUm">Twitter</a> microblogging</li><li>2007 (2007): <a href="/facts/WikiLeaks/rm4lC2cD">WikiLeaks</a> anonymous news and information leaks</li><li>2007 (2007): <a href="/facts/Google_Street_View/Ruqzal5A">Google Street View</a></li><li>2007 (2007): <a href="/facts/Amazon_Kindle/cmCbmvEs">Kindle</a>, <a href="/facts/E-reader/D7a76tKm">e-reader</a> and virtual bookshop</li><li>2008 (2008): <a href="/facts/Amazon_Elastic_Compute_Cloud/2EMwnvlS">Amazon Elastic Compute Cloud</a> (EC2)</li><li>2008 (2008): <a href="/facts/Dropbox/7D2Rhh32">Dropbox</a> cloud-based file hosting</li><li>2008 (2008): <a href="/facts/Encyclopedia_of_Life/E5Fz0Wrd">Encyclopedia of Life</a>, a collaborative encyclopedia intended to document all living species</li><li>2008 (2008): <a href="/facts/Spotify/wsTSvDD8">Spotify</a>, a <a href="/facts/Digital_rights_management/4AF8JmDt">DRM-based</a> music streaming service</li><li>2009 (2009): <a href="/facts/Microsoft_Bing/r2pIK5HT">Bing</a> search engine</li><li>2009 (2009): <a href="/facts/Google_Docs/y2RYkhAQ">Google Docs</a>, Web-based word processor, spreadsheet, presentation, form, and data storage service</li><li>2009 (2009): <a href="/facts/Kickstarter/J1R5A3f6">Kickstarter</a>, a <a href="/facts/Threshold_pledge_system/n2CoQ8ET">threshold pledge system</a></li><li>2009 (2009): <a href="/facts/Bitcoin/UJvqfray">Bitcoin</a>, a <a href="/facts/Digital_currency/ycholMaA">digital currency</a></li><li>2010 (2010): <a href="/facts/Instagram/33s91jnV">Instagram</a>, <a href="/facts/Photo_sharing/pyJS36yM">photo sharing</a> and <a href="/facts/Social_networking/qFIh6VT1">social networking</a></li><li>2011 (2011): <a href="/facts/Google%2B/YpruHrEK">Google+</a>, <a href="/facts/Social_networking/qFIh6VT1">social networking</a></li><li>2011 (2011): <a href="/facts/Snapchat/oIQ9tBh8">Snapchat</a>, <a href="/facts/Photo_sharing/pyJS36yM">photo sharing</a></li><li>2012 (2012): <a href="/facts/Coursera/5Kp5AIuX">Coursera</a>, massive open online courses</li><li>2016 (2016): <a href="/facts/TikTok/LC3FaCbX">TikTok</a>, <a href="/facts/Video_sharing/tNBgCRKy">video sharing</a> and <a href="/facts/Social_networking/qFIh6VT1">social networking</a></li></ul></td></tr></tbody></table>
The Domain Name System (DNS) is a hierarchical and distributed <a href="/facts/Name_service/6fsVdntu">name service</a> that provides a naming system for <a href="/facts/Computer/SQe1aK05">computers</a>, services, and other resources on the Internet or other <a href="/facts/Internet_Protocol/Qq6VeEal">Internet Protocol</a> (IP) networks. It associates various information with <a href="/facts/Domain_name/FDLD2m5G">domain names</a> (<a href="/facts/Identification_(information)/qwCtYbDW">identification</a> <a href="/facts/String_(computer_science)/4ChJu5WS">strings</a>) assigned to each of the associated entities. Most prominently, it translates readily memorized domain names to the numerical <a href="/facts/IP_address/z9V22Sw9">IP addresses</a> needed for locating and identifying computer services and devices with the underlying <a href="/facts/Network_protocol/5uady7cB">network protocols</a>. The Domain Name System has been an essential component of the functionality of the Internet since 1985.
The Domain Name System delegates the responsibility of assigning domain names and mapping those names to Internet resources by designating <a href="/facts/Authoritative_name_server/pUgmBMNW">authoritative name servers</a> for each domain. Network administrators may delegate authority over <a href="/facts/Subdomain/BM8N9jvH">subdomains</a> of their allocated name space to other name servers. This mechanism provides distributed and <a href="/facts/Fault-tolerant/rasrYlJk">fault-tolerant</a> service and was designed to avoid a single large central database. In addition, the DNS specifies the technical functionality of the <a href="/facts/Database_model/1okm9rHu">database</a> service that is at its core. It defines the DNS protocol, a detailed specification of the data structures and <a href="/facts/Data_communication/1yAhaANd">data communication</a> exchanges used in the DNS, as part of the <a href="/facts/Internet_protocol_suite/KNkxtSpw">Internet protocol suite</a>.
The Internet maintains two principal <a href="/facts/Namespace/9efXwMtV">namespaces</a>, the domain name hierarchy and the IP <a href="/facts/Address_space/EscyYKkP">address spaces</a>. The Domain Name System maintains the domain name hierarchy and provides translation services between it and the address spaces. Internet name servers and a <a href="/facts/Communication_protocol/5uady7cB">communication protocol</a> implement the Domain Name System. A DNS name server is a server that stores the DNS records for a domain; a DNS name server responds with answers to queries against its database.
The most common types of records stored in the DNS database are for start of authority (<a href="/facts/SOA_record/FcrD4SN1">SOA</a>), IP addresses (<a href="/facts/List_of_DNS_record_types/CgzuvJXy">A</a> and <a href="/facts/AAAA_record/CgzuvJXy">AAAA</a>), <a href="/facts/SMTP/TeCRKDpJ">SMTP</a> <a href="/facts/Mail_exchanger/9SJG5sbb">mail exchangers</a> (MX), name servers (NS), pointers for <a href="/facts/Reverse_DNS_lookup/b5qL5mN1">reverse DNS lookups</a> (PTR), and <a href="/facts/Domain_name_alias/DJFsfm3o">domain name aliases</a> (CNAME). Although not intended to be a general-purpose database, DNS has been expanded over time to store records for other types of data for either automatic lookups, such as <a href="/facts/DNSSEC/cL9zwhjj">DNSSEC</a> records, or for human queries such as responsible person (RP) records. As a general-purpose database, the DNS has also been used in combating <a href="/facts/Unsolicited_email/ARJr6Aem">unsolicited email</a> (spam) by storing <a href="/facts/Domain_Name_System_blocklist/XnKVleKE">blocklist</a>. The DNS database is conventionally stored in a structured text file, the <a href="/facts/Zone_file/pafY15EW">zone file</a>, but other database systems are common.
The Domain Name System originally used the <a href="/facts/User_Datagram_Protocol/dxLU0D6q">User Datagram Protocol</a> (UDP) as transport over IP. Reliability, security, and privacy concerns spawned the use of the <a href="/facts/Transmission_Control_Protocol/WW4sPrt9">Transmission Control Protocol</a> (TCP) as well as numerous other protocol developments.

Domain Name System open-in-new

Domain Name System