Also called rudiments. The practice of them helps one to develop some of the coordination required to play percussion instruments well, though the rudiments are generally for snare drum. If they're for something else, like mallets, they're called mallet techniques. Some instructors will emphasize rudiments right off the bat, and some will never touch on them at all. Personally, I think it is important to know them all, especially if you are a percussion major in college.