A state is an independent political entity composed of main four elements: population, territory, government, and sovereignty. States are the principal actors of international relations and basic units of the international system.
According to Oppenheim, “a state comes into existence when people are settled in a definite territory under its own sovereign government.” A state is a political entity defined in terms of territory, population, and government that effectively controls its territory and people.
States are those political entities that have a defined territory or an internationally recognized boundary, and a permanent population that is under the control of their own government, that have capacities to develop relations with other such entities. A nation is a group of people who have similar institutions, religions, languages, customs, and a sense of social homogeneity and mutual interest.
Different nations may exist in one state, or a nation may go beyond the territory of a single state. Thus, nations and states do not always share the same cultural and territorial boundaries. Social scientists have called a nation that has the same borders as a state a nation-state.
