A Realm can mean:

• A Realm, the dominions of a king (or queen), a kingdom.

• The word realm is often used in fantasy books or movies, primarly as a synonym for a world usually other than our own.

• In Java EE realm terms a database containing users, usergroups and their roles (sets of permissions to access server-resources). Optionally a realm manages user-passwords, certificates and authentication logic. Also a realm can refer to a web domain.

• Gaming - in Blizzard Entertainment's newer games (Diablo II. Warcraft III and World of Warcraft), the term realm is used interchangeably with a computer gaming server (some MMORPGs use the term Shard to describe a gaming server).

• Realmz is a fantasy adventure.

• The Realm was the name of a BBS and underground community of computer hackers based in Melbourne, Australia in the late 1980s. Its most notable members were Phoenix, The Force and Electron, who were both arrested by the Australian Federal Police in April 1990 in Australia's first major computer hacker bust.

• Various theories have been supposed which used realms to explain how time moves.