Imagine you have a procedure, routine, or an algorithm that completes a task -- like drawing a square.   If you needed to recall that algorithm many times throughout a program, you could create function.  When creating a function, you give it a name  and define it -- or create the rules or steps for it to follow.  You can then just use that function block in your code.  In the example to the left, we want the artist (sprite) to draw a square.  We created a function called Square and used our code blocks to define what that looks like.  We can now use the one block called Square instead of the repeat, move, and turn blocks that define the square.  Functions can help our programs become shorter and more efficient.