[OmegaHN]

I suppose you have to know the general idea of a Version Control System (VCS) first before you can understand how Git does version control. I'll try my hand at it.

A Version Control System is a software system that uses files to save different versions of your source code (really, it can save any file, but it works best with source code). The system also lets you revert back to an old version of your code, so you can try something radical out on your code knowing that you have a safe version tucked away in your version control system.

A 'commit' is when you tell the VCS to take a "snapshot" of your files and then save that in its system. Git implements 'commits' with three-location system: the working index (the files on your computer), the staging index (Git's log of what files you want to change), and then the actual commit index (where all the versions are saved). When you stage a file, you tell Git to add the name of that file to it's internal log, telling Git that you want that file to be saved in a version. After you have told Git what files to save (by "staging" them), you can commit (with 'git commit') to save that snapshot of your staged files. Later on, you can revert to the snapshot through git commands.

Hope this helps!