Domain

The term Domain or Domain Name carries a number of related meanings:

Domain name can be the name that identifies a computer or collection of computers on the Internet. These names appear as a part of a website's URL, for example, www.superbhosting.net. This type of domain name is also called a hostname.
The domain name is the product that domain name registrars provide to their customers. These names are often called registered domain names.
Domain names can also be names that are used for other purposes in the Domain Name System (DNS), for example the special name which follows the @ sign in an email address, or the Top-level domain names like .com.