A nation-state is a political entity characterized by a defined territory, a permanent population, a government, and the capacity to enter into relations with other states. It combines the concepts of a nation, which refers to a group of people sharing common cultural traits, and a state, which is a political organization with authority over a specific area. Nation-states often seek to promote a sense of national identity among their citizens, fostering unity through shared language, culture, and history. Examples of nation-states include France, Japan, and Brazil, each with distinct cultural identities and governance structures.