What does the term "nation-state" refer to?

The term "nation-state" refers specifically to a political entity characterized by a defined territory and a permanent population governed by a centralized government. This concept merges the political and national identity aspects, where the state's boundaries typically correspond with a cultural or ethnic group's identity, although the two do not always align perfectly.

In many cases, a nation-state is regarded as the ideal unit of political organization, where the state's governance aligns with a particular nation's cultural identity and values. This includes the recognition of sovereignty and the ability to create and enforce laws within its territory.

Options that describe a cultural identity independent of territory, a collection of ethnic groups, or a political alliance between nations do not accurately capture the essence of what constitutes a nation-state. These alternatives highlight aspects of social organization or collaboration, but they do not encompass the fundamental attributes of governance, territorial integrity, and political sovereignty inherent in the definition of a nation-state.