A territory is a defined area (including land and waters), usually considered to be a possession of an animal, person, organization, or institution.

• In biology, an organism which defends an area against intrusion (usually from members of its own species) is said to be territorial. For further details see territory (animal)
• In politics, a territory is an area of land under the jurisdiction of a governmental authority. Territory can, though, include any geographical area under the jurisdiction of a sovereign and does not have a political division status. The remainder of this article deals with political territories.
• In psychology, Environmentalists study Territorial Behaviour to understand which Territory an organism defends and why. Territorial Behaviour is defined as;

"The actions or reactions of a person or animal in response to external threats towards the space that is defended by that person or animal."

Types of territories include:

• A legally administered territory, which is a non-sovereign geographic area that has come under the authority of another government. For example, American Samoa is a territory of the government of the United States. With regard to the Canadian provinces and territories, the major difference between a Canadian province and a Canadian territory is that the federal government has more direct control over the territories, while the provinces are run by provincial governments empowered by the constitution. See also Australian States and Territories.

• An occupied territory which is a region that is under the military control of an outside power that has not annexed the region. An example of an occupied territory is Iraq after the American invasion of 2003 or Germany after World War II.

• A disputed territory, which is a geographic area claimed by two or more rival governments. For example, the territory of Kashmir is claimed by both the governments of India and Pakistan.

• A claimed part of Antarctica.