What is Domain Name?
The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine.
For example, Apple Computer (Domain Name "apple.com") has Web sites at www.apple.com and store.apple.com. Each of these sites could be served on different machines.