Aliases permit the association of multiple names to a single host.
Aliases may be useful when a host provides several different services or to transition a host to a new name while preserving compatibility via the old name. Domain A Domain is a collection of Hosts that are typically related via some logical organization like geographic or political boundaries, government bureaucracies, and corporate divisions. However, a Domain does not require a particular organization, any set of Hosts may be collected into a Domain. Note that Domains themselves may be divided into sub-Domains, and so on. Domain Name Domain Names are the names assigned to collections of Hosts on the Internet.