Alternatively referred to as a domain suffix, TLD is short for top-level domain and is the trailing portion of the domain. For example, when visiting computerhope.com, ".com" is Computer Hope's TLD. The original TLDs are: .com, .gov, .org, .net, .mil, .edu, and .int.
The portion of the domain directly in front of the top-level domain is known as the SLD (second-level domain).
See our Internet domain suffix listing for a full listing of top-level domains.