Configuring Domain Name System (DNS) servers

The Internet domain structure

In the United States, the Internet domain name space is divided into several organizational and geographical top-level domains. Other countries follow similar structures.

In the US, top-level domains include:

COM: commercial organizations
EDU: educational organizations
GOV: government organizations
INT: international organizations
MIL: military departments
NET: networking organizations
ORG: miscellaneous organizations

The top-level domains are shown here in upper case. In fact, domain names are case-insensitive. That is, the COM domain is equivalent to the com domain and is usually written in lower case.

Geographical domains generally follow the ISO 3166 standard, which contains abbreviations for each country (for example, ca for Canada, ch for Switzerland, and it for Italy). An exception is the domain uk (United Kingdom) which is used for Great Britain rather than the value gb defined by the standard.