It's a way of structuring your code in order to make it seem more like the class structure your probably used too.
My suggestion is although in most cases you will only use one instance of the module, scroll down to the bottom and set up your code to be able to instantiate classes. In the long run this makes your code far more readable and doesn't take much more effort to set up.
The Revealing Module Pattern is based on a pattern referred to as the Module Pattern. It makes reading code easier (in my opinion anyway) and allows it to be organized in a more structured manner.