My brother loves playing something called cue sports but I don't know much about what that is. Is it like golf or pool?
It's basically a broad term for a variety of games of skill generally played with a cue stick, like billiards or pool for example.
Oh awesome. Is it a popular sport in the United States?
I think it's a fairly niche sport to be honest, I know that billiards means different things depending on if you're in Britain or the US though, oddly enough.