TLD stands for “Top Level Domain”. It is the part of the domain name which comes after the dot. For example, in GOOGLE.COM, the TLD is .COM.
There are basically two types of TLDs.
One are the ‘Generic’ top level domains (gTLDs) which include the well known .COM, .NET, .ORG, .BIZ, .BIZ and .NAME.
The second type are the so called ‘Country Code’ top level domains (ccTLDs). Every country has been assigned a ccTLD. Some well known ccTLDs are .CO.UK for the United Kingdom, .TV for Tuvalu, .WS for Western Samoa, .CA for Canada and .CN for China.
Every TLD has a ‘Registry’ which is an organization responsible for maintaining the online database. The database contains the WHOIS information about every domain in that TLD. For example, the .ORG Registry is the Public Interest Registry with offices in Reston, Virginia, USA.
Follow this link to my article if you’re interested in more about TLDs, the domain name system (DNS) and the essential role they play in bringing web sites to your browser.