The term domain name has multiple related meanings:
A name that identifies a computer or computers on the internet. These
names appear as a component of a Web site's URL. This type of domain
name is also called a hostname.
The product that domain name registrars provide to their customers.
These names are often called registered domain names.
Names 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 domains like .com, or the names used by the Session Initiation
Protocol or DomainKeys.
