The primary difference between a state and a nation lies in their definitions: a state is a political entity with defined borders, governance, and sovereignty, while a nation refers to a group of people who share common cultural or ethnic characteristics. A state can encompass multiple nations, as seen in multinational states, while a nation may not necessarily have its own state or recognized borders, leading to movements for self-determination. This distinction is important for understanding issues related to nationalism, identity, and the implications of governance over culturally diverse populations.