Git is version control software. It is really collaboration software. We have all edited the wrong version of a file. Or screwed something up and had to start all over. Or sent the wrong version to a boss or colleague. Git allows you to collaborate, resolve differences, experiment and revert to prior versions if an experiment goes wrong. As in science, most experiments fail. This saves an enormous amount of time, the more work you do. It also allows us to save an offsite copy of our code and data in case you spill ice tea all over your keyboard. (Yes, I’ve done that.)