Use of Domain in Web Site Hosting

A domain name is a component of a Uniform Resource Locatorr (URL) used to access web sites.
A domain name may point to multiple IP addresses to provide server redundancy for the services delivered. This is used for large, popular web sites. More commonly, however, one server at a given IP address may also host multiple web sites in different domains. Such address overloading is possible through a feature in the HTTP version 1.1 protocol (but not in HTTP 1.0) which requires that a request identifies the domain name being referenced. This enables virtual web hosting, commonly used by large web hosting services to conserve IP address space.