Distinguish between a state and a nation?

Depending on the source, there are 189, 191, 192, 193, 194 or 195 states in the world today and 800+ nations.

State: The accepted definition of a state was supplied by Max Weber in his book Politics as a Vocation: "A sovereign entity (rules itself), within a defined/specific territory (in defined borders), that holds a monopoly of the legitimate use of violence in the enforcement of its order. An empire does not have borders as it chooses to continually advance them. A state does not necessarily rule a people with a common culture, it is merely a political concept. Examples of a state: Iraq/Yemen/any state in the United Nations.

A nation is a body of people who share a real or imagined common history, culture, identity, religion, morality, language, traditions, ethnicity or ethnic origin; typically inhabit a particular country/territory/region. Examples of a nation: the Kurds, which reside in northern Iraq and parts of Turkey; the Basque, which inhabit parts of northern Spain and southern France; the Palestinians.

Nation-State: Countries where the social concept of "nation" coincides with the political concept of "state" are called nation-state. Examples of a nation-state: France, USA, Israel.