domain

Noun

domain (plural domains)

1. A geographic area owned or controlled by a single person or organization.
   • The king ruled his domain harshly.
   • Bears and other ferocious beasts resented man's intrusion into their domain; so, too, did the Blackfoot Indians and other tribes, whose savage hostility was a constant menace to the lives of the toiling engineers.1954 February, Trevor Holloway, “Canada's Transcontinental Routes”, in Railway Magazine, page 128

   Synonyms:

   demesne

2. A field or sphere of activity, influence or expertise.
   • Dealing with complaints isn't really my domain: get in touch with customer services.
   • His domain is English history.
3. A group of related items, topics, or subjects.
   • Some of the most beautiful and thus appealing physical theories, including quantum electrodynamics and quantum gravity, have been dogged for decades by infinities that erupt when theorists try to prod their calculations into new domains. Getting rid of these nagging infinities has probably occupied...2012 January, Michael Riordan, “Tackling Infinity”, in American Scientist, volume 100, number 1, archived from the original on 30 Apr 2013, page 86
4. The set of input (argument) values for which a function is defined.
   1. (broadly) The set A; The subset of A consisting of elements a of A such that there exists an element b in B with (a,b) in R.
5. A ring with no zero divisors; that is, in which no product of nonzero elements is zero.
6. An open and connected set in some topology. For example, the interval (0,1) as a subset of the real numbers.
7. (Internet) Any DNS domain name, particularly one which has been delegated and has become representative of the delegated domain name and its subdomains.
   • Every name in the DNS tree is a domain, even if it is terminal, that is, has no subdomains.2000, BIND 9 Administrator Reference Manual (9.3.2), Internet Software Consortium https://web.archive.org/web/20060619063455/http://www.bind9.net/manual/bind/9.3.2/Bv9ARM.ch01.html
8. (Internet) A collection of DNS or DNS-like domain names consisting of a delegated domain name and all its subdomains.

   Synonyms:

   domain name, hostname

9. A collection of information having to do with a domain, the computers named in the domain, and the network on which the computers named in the domain reside.
10. The collection of computers identified by a domain's domain names.
11. A small region of a magnetic material with a consistent magnetization direction.
12. Such a region used as a data storage element in a bubble memory.