What does underhand and overhand mean in volleyball?

Answer 1

Underhand is where your hit the ball by reaching forward underneath it. Overhand is where you hit the ball above your head. Which one you use would have to depend on where you are relative to the ball. If it is above your head, you will have to use overhand (maybe you will have to jump), while if the ball is going to hit the ground in front of you, you will have to use the underhand hit (and you may have to dive for it).