Zone defense is different from man-to-man defense. Instead of guarding a particular player, each zone defender is responsible for guarding an area of the floor, or "zone", and any offensive
This is a drill I use with elementary school boys (2nd to 4th grade so far) that has been popular. It teaches the boys to move without the ball, and to move/weave toward the basket (to be in a position to shoot). I've found this drill works best with man-to-man defense.