How does one do this Photoshop Technique?

Does anyone know what it is called, or how to do this technique: A series of pictures (10 pictures for example) like of someone shooting a basketball but not moving their body so the only thing that moves in all the frames is the basketball. How does one combine all of those pictures together so it shows all of the basketballs in one frame? Is that a ps technique or what?How does one do this Photoshop Technique?
All you have to do is have the person shoot one basketball and catch it when the person has their arms where you want them.





Then, in Photoshop, you select the basketball (wherever it is) and duplicate it on a new layer. Keep duplicating the basketball layer over and over, each time moving it to a another location and rotating the ball.





Each new layer needs to have the opacity reduced by about 50% (or whatever % looks best) to make it look like it is a stop motion effect.





That's the basics of one way to do it.How does one do this Photoshop Technique?
The answer above me is just as good as I could explain it, but I thought a couple things could be added/changed. First if you don't know how to select the ball use the magic wand tool just click it and it should be selected, also if you want it to look like he's shooting the ball but not moving, instead of decreasing the opacity every time you move the ball on a new layer (the master opacity control is in the layers window in the upper right hand corner) decrease it gradually from the basket back that way it looks like he's shooting it.