VCSs (Version Control Systems) have been around for a long time, and should absolutely be a part of every developer’s toolbox. If you’re not using a system to keep track of your files, you shouldn’t be programming. They have evolved and grown along with the code bases they track. Git hardly the only solution out there, but it’s well-thought-out and evolved.
Git has actually been around for quite a while and hasn’t been surpassed in features, relative ease of use (yaay cheap branches) and breadth of tools. Even with the other VCSs out there, git is pretty much the de-facto choice, at least for me.
I not only use git to track my code at work, I use to to track the files of my personal projects, text editor configurations, and a few other things. It’s a great system and truly indispensable. After the OS and a text editor, it’s what I install on every machine.