What is a TLD (Top Level Domain)?

A top level domain (TLD) refers to a given domain name that falls right at the peak of the domain name system which is usually hierarchical in structure. In more technical terms, TLDs are usually saved in the root folder of the name space. Another way of looking at it is that it is the last part in the domain names that are in the lower levels in the domain name system hierarchy. For instance, in the domain name www.hubpages.com, .com can be said to be the Top Level domain.

ICANN (internet Corporation for Assigned Names and Numbers) is the body that is in charge of maintaining the DNS root folder. ICANN is mandated with the responsibility of managing the top level domains that exist.

Traditionally, the top level domains were categorized into three broad categories namely; country, category and multi-organizations. However, the growth of the internet in the past decades has led to the creation of other top level domains. For instance, a .Africa TLD has been proposed to serve the African community. There are many other TLDs that have been proposed and it is now possible for large organizations to register their own TLDs.

It is important to point out that there are some top level domain names that are reserved and the main reason for this is to avoid unnecessary confusion when registering the domains. For instance, you can not register a TLD with the name example. This name is reserved since it is commonly used to give an example of a domain. E.g., www.example.com, www.example.org etc. Another reserved word is localhost. Localhost is the default hostname and this name has been reserved in order to avoid conflict. The other two reserved words are test (used for tests) and invalid.