DNS stands for Domain Name System. The DNS is the system by which all Internet service addresses are created, maintained, and used.
Under the Domain Name System, an Internet address has four elements; a server prefix, a domain name, a domain suffix (or extension), and a country code (the only optional element).
The Domain Name System, or DNS, was implemented by ARPAnet in 1984, and is managed by InterNIC (the Internet Network Information Center), based in Virginia. InterNIC, in turn, is operated by ICANN, the non-profit corporation that oversees the DNS.
The DNS makes the Internet more user-friendly, because it uses names and plain English to identify server computers, individual files, and e-mail addresses. Imagine if all web sites, for instance, had to be identified by their IP addresses! Finding what you want to find on the 'Net (and advertising on the 'Net) would be a very difficult proposition without the DNS.