Nation, state, and nation-state have a different meaning. Nation is a large group of people that has put together as culture, language, ideology and history. State means political machinery that constitutes land, population, government and sovereignty or recognition from another state. In Europe, almost all nation have attributed to nation-state. On the other hand, in Africa country gaining independence attempts to make a common sense of nationalism. Thus these countries are just the state but aren't actually the nation-state.