A top-level domain (TLD) is at the highest level in the hierarchical Domain Name System of the Internet. They are organized in three groups Countries, Multi-organizations and categories. Some of the TLD's include .com, .net, .org, .gov and all the country specific TLD's such as .ca. There are many others. The Internet Corporation for Assigned Names and Numbers (ICANN), has management responsibility of the TLD's. Here is an example of what part of a domain name the TLD is. The .com at the end domain name www.loaddns.com is the TLD.
See Also:
Domain Name System
Domain
ICANN