Git is a nice version control system. It allows to commit changes in files. Git saves it in a tree system since it uses branches to allow merges.
How it works
As I said, git uses branches it looks like this There you see that you have the main branch also known as the "master branch". Which is the base branch.
How to work with branches
From the base branch, you usually have feature-specific branches. For each feature and issue.
You can use git with a desktop GUI tool or in a terminal. How you do this, is covered in another article.