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

• 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 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 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 political 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. The same distinction applies between States and territories of Australia, although Australia also distinguishes the mainland territories from the small insular possessions known as external territories. Under British rule, Hong Kong was often referred to as a territory, rather than a colony from about the 1960s onwards.