If you are creating a game, you need to download GitHub to your computer. As we create our own game, GitHub has allowed us to work on the same project using different computers. This is especially valuable if you are working in a group. You have to be careful though, because you can't work from two different computers at the same time or else things could get screwed up (I don't exactly what would happen, and I don't want to risk it).
GitHub also allows you to save different versions of your game. This is nice because if you are working on your game and things go wrong, you can always go back to an earlier version (which is going happen to us at some point). It is nice to be able to try new things in your code without having to worry too much.
Here is a link to their website. Please check it out- it really will make a difference in your project! https://github.com/