A federation is a political entity characterized by a union of partially self-governing states or regions under a central (federal) government. In a federation, the self-governing status of the component states, as well as the division of power between them and the central government, is typically constitutionally entrenched and may not be altered by a unilateral decision of either party, the states or the federal political body - wikipedia
Alternatively, federation is a form of government in which sovereign power is formally divided between a central authority and a number of constituent regions so that each region retains some degree of control over its internal affairs.
"Federation" may also refer to:
*Federation (information technology), the standardization of information systems, or their means of inter-connection.
**Federated identity, many (generally un-federated) methods of allowing user's data in one system to be transferred to, and used by, another
*Federation architecture, an Australian architectural style (c. 1890 - c. 1915)
*Federation (spacecraft), a Russian spacecraft currently in development
# See also