What are Top Level Domain Names?

The top-level domains such as .com and .net and .org are the highest level of domain names of the Internet. A top-level domain is also called a TLD. Top-level domains form the DNS root zone of the hierarchical Domain Name System. Every domain name ends in a top-level or first-level domain label.

When the Domain Name System was devised, in the 1980s, the domain name space 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[ernment], Edu[cation], Com[mercial], Mil[itary], Org[anisations],Net[work], and Int[ernational].

During the growth of the Internet, it became desirable to create additional generic top-level domains. As of October 2009, there are 21 generic top-level domains and 250 two-letter country-code top-level domains.In addition, the ARPA domain serves technical purposes in the infrastructure of the Domain Name System.

During the 32nd International Public ICANN Meeting in Paris in 2008, ICANN started a new process of TLD naming policy to take a "significant step forward on the introduction of new generic top-level domains." This program envisions the availability of many new or already proposed domains, as well a new application and implementation process. Observers believed that the new rules could result in hundreds of new top-level domains to be registered.