- State (polity) : A supreme corporate entity that has a legal existence that is distinct from its constituents and that exercises sovereign political authority over a country.
- Country : Nation, state, region, or territory, or large tract of land distinguishable by features of topography, biology, or culture.
- Sovereign state : Political association with effective internal and external sovereignty over a geographic area and population which is not dependent on, or subject to any other power or state.
- Nation state : Form of state that derives its political legitimacy from serving as a sovereign entity for a nation as a sovereign territorial unit.
- Pseudostate : A term put forward by the author and journalist Adam Hochschild to refer to political states or regions where power rests with a government or organisation either outside the country or in some way unaccountable - for example, a local militia.
- Small state : A term used by the secretariat of the Commonwealth of Nations to denote a country with a population not greater than 1.5 million.
- Core state : Within a civilization, one or more nations that provide a dominant cultural influence
- Failed state : A nation or quasi-nation unable to deliver minimal governance services to its citizens; there may not even be a functioning government
- Weak state : A nation whose government or institutions are unable, or unwilling, to provide a significant set of essential public services, including just and legitimate government, physical security, food and health, and minimal economic development; contrast with failed state, which provides essentially none
- Islamic state : Nation with a government and legal system conducted in accordance with Islamic religious law.
- SS State : A term used in historical analysis of Nazi Germany, referring to Heinrich Himmler's increasing development of an Schutzstaffel state-within-the-state, with its own ethos, economy, and racial standards superior to Germany as a whole; introduced in the book Das SS-Staat by Eugene Kogon
- U.S. state : Any of 50 political entities that make up most of the territory of the United States of America and share sovereignty with that nation's federal government.
- Steady state : A situation with constant system properties despite non-vanishing energy flow.
- Mixed state : A concept for describing a quantum mechanical system whose state is not known precisely, but can possibly be in a collection of pure states, with a certain probability of being in one of the pure states.