All hosts on the Internet, or any TCP/IP network for that matter, have an assigned 32-bit IP address. Most hosts have a name, as well, since host names are easier to remember than host addresses. The Domain Name System (DNS) is the distributed database that contains the names and addresses of all reachable hosts on a TCP/IP subnet, including the Internet.
Most, but not all, Internet service providers (ISPs) will set up and maintain the DNS information for their customers. There are several reasons, however, that a customer may want to operate their own DNS. This article will describe Internet domain names and the structure of the DNS, followed by a brief tutorial about creating and maintaining the DNS information.