A political unit consisting of a government that has sovereignty presiding a well defined teritory.

The description you provided refers to a "State". In political science and international law, a State is a political unit that has sovereignty over a well-defined territory and the people within it. It has a structured government that creates and enforces laws. The government has the authority to govern its own affairs without interference from outside entities. This includes the power to establish and regulate foreign and domestic trade, declare war, establish peace, and conduct other affairs with other states. It is recognized by other states as a state in the international system.