What is a Domain Name?
Domain names provide more memorable names to use in place of numeric IP addresses. By allowing the use of unique alphabetical addresses instead of numeric ones, domain names allow Internet users to more easily find and communicate with web sites and other server-based services. Domain names are restricted to the letters "a" through "z" (case-insensitive), the digits "0" through "9", and the hyphen, with some other restrictions.
Below is an example illustrating the difference between a URL (Uniform Resource Locator) and a domain name:
URL: http://www.hostrocket.com/index.html
Domain name: www.hostrocket.com
Registered domain name: hostrocket.com
Domain name: www.hostrocket.com
Registered domain name: hostrocket.com