Examining the code

Let's look closely at the line of code that we wrote:

renderer.enabled = false;

The semicolon at the end of the line is like the period at the end of a sentence. Nearly all single-line statements must end in a semicolon or the code might break. When code breaks, Unity uses a special popped-up window called the console to tell us about it. When you have code that throws an error, we say there is a bug in your code.

In order to understand the rest of that line, you need to realize that there is a LOT of code going on behind the scenes that you can't see. It looks like a bunch of pretty pictures to you and me, but the Unity team had to write code to make it look that way. Behind each instance of your GameObject, and behind the Unity program itself, there are thousands of lines of code telling your computer what to show you.

Renderer is one such piece of code. When you set the enabled property of your ball's renderer to false, you're saying that you don't want Unity to draw the triangles in the mesh that makes up your ball.