area of land under a certain jurisdiction
A territory (plural: territories, from the word terra, which means 'land') is an area which belongs to a person, organization, institution, animal, nation or state. In international law, a "territory" is an area of land which is outside the borders of a nation, but owned by that nation. Examples are: Puerto Rico as a U.S. territory, or Bermuda as a territory of the UK.
General examples of territories are states controlled by a federated government (such as Germany or the counties of a state within the States of the United States), a unitary state such as France, an occupied territory (land which has been invaded by the military of another country) or a disputed territory (such as Kashmir, which both India and Pakistan believe is theirs).