system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What exactly is the difference between a nation, a country, and a state?
gpt
They all refer to land and people under some form of administration, usually with centralized control, that operates largely independently of other lands and peoples. State often either refers to the operations of a nation or a constituent territory of that nation, though, and does not often refer to a wholly independent region. Country and nation refer to regions that act independently of one another. Country is often used to describe the geopolitical region - that is, the borders. Nation is often used interchangeably, but refers more to the sociopolitical region - that is, the people.

The question of what lands *are* independent entities is hard to define, since there is no one organization responsible for them all, though the United Nations tries to fill that role. That's why the UN recognizes a different number of countries than the USA does. Roughly speaking, there are about 200 countries.