ZackM said:
My favorite is when someone says something like "Player X doesn't jump as high, he just has better hang time."
It's shocking how many times I've seen some variation of that.
I think this is actually a real phenomenon they are just describing it poorly.
The reason is that some people have much better balance and body control than others, so a larger portion of their time spent in the air they are actually balanced enough to make a basketball play, whereas some players don't have this balance and they are only capable of making a play while in the air for a a much shorter time.
So when people say player A has more hang time than player B, what they mean is that Player A has more time to make a play in the air than player B, so it feels like he is in the air longer.