Domain Name Primer


Every time you are surfing the net you encounter something known as TLDs. After all what is it and how is it used?  TLDs are the Top Level Domains and they are the last part of an Internet domain name. Let’s take an example, in the domain name, the top-level domain is the three letters “com”.

It’s actually not that complicated!

The top-level domains (TLDs) are the highest level of domain names of the Internet.  The Domain Name System was created in the 1980s, and then the domain name space was divided into two main groups of domains. The country code top-level domains (ccTLD) were primarily based on the  territory codes of ISO-3166 country abbreviations. On the other hand, a group of seven generic top-level domains (gTLD) was implemented which represented a set of categories of names and multi-organizations.

gTLDs – Generic domains

A gTLD (generic top level domain) is a top-level domain and is used in particular by a specific type of organization. These generic TLDs are three or more letters long, and they’re named to be a good fit to the organization.
When top-level domains were first implemented, in January 1985, there were seven gTLDs:
•    ARPA —  Advanced Research Projects Agency
•    COM — commercial
•    EDU — educational establishments (primarily U.S.)
•    GOV — U.S. government
•    NET — network infrastructure
•    ORG — non-profit organizations
•    MIL — U.S. military

You must have come across the most popular domain extensions on the web –  .BIZ, .NAME, .MOBI, etc. They are all known as generic top-level domains (gTLDs) and are open for registration to all users worldwide, regardless of their citizenship, residence or age.

•    unsponsored top-level domains: domains operating directly under policies established by ICANN processes for the global Internet community.
•    sponsored top-level domains (sTLD): The private organizations proposed  and sponsored these domains Use is based on community theme concepts.
•    infrastructure top-level domain: It’s a group that consists of one domain, the Address and Routing Parameter Area (ARPA). It is managed by IANA.

ccTLD – Country Code Top-Level Domain

ccTLD is an Internet top-level domain generally used or reserved for a country or a dependent territory.
Each country has a unique two-character abbreviation which is added at the end of the domain name (e.g. .us for US, .de for Germany, .uk for United Kingdom, .in for India, etc). Some countries have sold the rights to their ccTLDs (e.g. Tuvalu and .tv).

A new add-on to this is a group of internationalized domain name (IDN) top-level domains that has been installed under test for testing purposes. The countries and territories may apply for IDN ccTLDs from November 2009.

Refer to the following links for the authoritative list of currently existing TLDs in the root zone: