Answer:
The definition of something like a nation-state is famously elusive. Among the most prominent historians of nation-states as well as democracy, Anthony Smith, concluded that what a country is a nation-state even so that when a specific ethnic and religious group resides within its borders, and the county's borders are congruent with the ethnic as well as cultural populace's borders.
The expression "nation-state" means that the two are related in the sense that a state has elected to follow and support a particular cultural community. The federal state, metropolis, republic, confederacy, as well as other state structures in which it can intersect can be correlated and contrasting with the notion of a nation-state. The most important difference is the association of a group of individuals with a particular culture.