Domain

Domain has several meanings:

some kind of territory, such as (for example) a demesne or a realm
synonymous with field, e.g. the domain of computer science
public domain, a body of works and knowledge without proprietary interest
domain of discourse in symbolic logic
eminent domain, the power of government to confiscate private property for public use
in biology, a domain is a subdivision even larger than a kingdom
in biochemistry and protein science, a domain is an autonomously folding functional module of a protein
in physics a domain is a region of a solid inside which a property is uniform (for example magnetic domain in ferromagnetism)
application domain , the kind of uses a computer program or something else is used for
domain name, as used by a URL or Uniform Resource Locator.

Information technology

In information technology domains can occur as:

a broadcast domain in computer networking
a domain name, part of the name of a machine on the Internet
- a Windows Server domain, a centrally-managed group of computers using the Windows operating system

In mathematics domain can refer to:

The original etymological implication of the word domain carries the idea of something ruled. Compare dominion.