Linux.com - https://www.linux.com/news/tutorial-git-absolutely-everyone
Imagine you have a brand new project. Naturally, you plan to store all related files in a single new directory. As work progresses, these files will change. A lot. Things will get disorganized, even messy, and at some point even completely fubar. At that point, you would want to go back in time to the most recent not-messy, still-working version of your project — if only that were possible!