Lol we got one topper boy who asks his doubts in class😈... anyway I'll explain. Autotrace is used to create a dedicated mask around the object. Now you may argue what's the problem with manually masking, but here's the thing you can't possibly draw a perfect mask around geometrical objects bcs you're shaking hand cannot create good masks can it? Also we use it when we're dealing with maks for a single frame. But for moving frames you need to first rotobrush the object then you can apply autotrace on the extracted object. NOW IF YOU DON'T UNDERSTAND ANY OF THESE THEN DON'T PANIC SOMETHINGS CANNOT BE UNDERSTOOD. SO JUST FOLLOW THE PROCESS😇...PEACE✌