Information :

What is the Domain Name System?

The Domain Name System (DNS) helps users to find their way around the Internet. Every computer on the Internet has a unique address - just like a telephone number - which is a rather complicated string of numbers. It is called its "IP address" (IP stands for "Internet Protocol"). IP Addresses are hard to remember. The DNS makes using the Internet easier by allowing a familiar string of letters (the "domain name") to be used instead of the arcane IP address. So instead of typing 207.151.159.3, you can type www.internic.net. It is a "mnemonic" device that makes addresses easier to remember.

Domain Names have a variety of basic rules:

.COM, .NET and .ORG Domain Names Terms
.COM - to be used for commercial and personal sites
.NET - recommended for companies involved in Internet
.ORG - recommended for not-for-profit organizations

Use only letters, numbers, or hyphen ("-")
Cannot begin or end with a hyphen
Must have less than 63* characters, not including .COM, .NET and .ORG
*.com, .net and .org names exceeding a total of 26 characters are supported by most browsers. However,certain browsers, email programs and other related applications may not support domain names over 26 characters.