Nation state

The nation state is a certain form of state that a territory on which mainly one nation is located. The state is a political entity (the government, etc.); the nation is a cultural and/or ethnic entity. The term "nation state" means that both are on the same territory, which distinguishes the nation state from the other types of states that had existed.
Examples.
Clear examples of nation states include:
Before nation-states.
In Europe, in the 18th century, the classic non-national states were empires of many ethnicities, (Austria-Hungary, the Russian Empire, the Ottoman Empire, the French Empire and the British Empire).