Between 1984 and 1985, the Domain Name System of the internet was deployed under the guidance of Jon Postel to replace the host.txt system. The DNS contains resource records that maps easy to remember domain names to unique numeric addresses assigned to every computer. It also serve as a distributed database for information about resources on the Internet.
The initial top level domain names was introduced through the Internet Working Group Domain Requirements (RFC 920) authored by Jon Postel and .Joyce Reynolds in 1984. The original top level domain names include: .arpa (intended to be transitional for the ARPA-Internet), .com (commercial), .edu (education), .gov (government), .mil (military), and .org (organization) as well as two-letter (alpha-2) names identifying countries based on the ISO 3166-1 (ISO Standard for Codes for the Representation of Names of Countries. In 1985, when the TLDs were implemented .net was added and subsequently in 1988 the .int was added for international organizations.
In 2000, during the ICANN meeting in Yokohama the Domain Name Supporting Organization (DNSO) proposed the introduction of new TLDs under a new policy. Seven new TLDs were implemented between 2001 to 2002.Four new unsponsored TLDs .biz, .info, .name, and .pro and the three other new TLDs, .aero, .coop, and .museum were sponsored.
Types of TLD
- Country Code Top Level Domains (ccTLD) is composed of two-letters such as .us, .ca, .de, .jp and many others. There are 250 established ccTLDs, which represent countries and territories around the world and they are operated by designated managers based on the country policies adopted to meet the economic, cultural, linguistic, and legal circumstances of the country or territory involved.
- Generic Top Level Domain (gTLD)is composed of three or more characters such as .com, .jobs, .info, .aero etc. The gLTD has two categories:
- Sponsored Top Level Domain (sTLD)
- Unsponsored Top Level Domains (uTLD),
- The .arpa TLD is a special domain used for technical infrastructure purposes which is administered by ICANN in collaboration with the internet technical community under the Internet Architecture Board's supervision.
List of Sponsored Top Level Domains
- .aero - sponsored by SITA
- .asia - sponsored by DotAsia Organisation
- .cat - sponsored by Fundació puntCAT
- .coop - sponsored by DotCooperation LLC
- .edu - sponsored by US EDUCAUSE
- .gov - sponsored by US General Services Administration
- .int - sponsored by IANA
- .jobs - sponsored by Society of Human Resource Management
- .mil - sponsored by US Department of Defense Network Information Center
- .mobi - sponsored by dotMobi
- .museum - sponsored by Museum Domain Management Association
- .post - sponsored by Universal Postal Union
- .tel - sponsored by TelNic Ltd.
- .travel - sponsored by Tralliance Corporation
- .xxx - sponsored by International Foundation for Online Responsibility