Top-level domains
The extensive use of the internet has led to a variety of dos and donts coming into the picture over a period of time. The exclusive use of the online space desired has led to a number of tools being maintained in place for better and more effective control. One such tool is the TLD or top level domain name after every regular id. The TLD is always either one of a small list of generic names with distinct three or more characters or a two-character territory code. The latter is based on the ISO 3166, with a few exceptions.
The new codes are integrated case by case, gradually. Top-level domain names are also sometimes referred to as first level domain names. The top level domain names make the ids easily recognizable and enhance end user applications. The gradual integration of the codes and the ISO 3166 regulations are all kept in place for the user to benefit from the application.