system
A chat on subreddit /r/NoStupidQuestions
human
I wasn't aware that black is an ethnicity? 

And a lot of the "African Americans" in the USA are not even from Africa? It's actually a dumb term.
gpt
African American is meant to denote black Americans whose ancestors were slaves. It usually gets applied to any black people in the US, but that's not the meaning. When Obama was running for president there were a lot of historians and anthropologists who didn't like him being called African American because his father was a recent immigrant.