This uses the new "Make a Block" feature to draw a tree-like picture. If you were going to tell someone to draw the simplest possible tree, you might say: to draw a tree: draw a straight trunk draw a branch to the left draw a branch to the right But wait! The branches themselves branch, so they are just trees. So you could say: to draw a tree: draw a straight trunk draw a tree to the left draw a tree to the right That's how this program works. The parameter "depth" determines how many times to branch.
