Git is a very powerful and useful version control system to keep track of changes in documents. The installation on macOS with Homebrew is easy.
I found Git to be extremely useful when you write a LaTeX document like your thesis. You can then use Git to store the history of your files and you will never miss a reference.
To install Git, you can use Homebrew:
$ brew install git
Afterwards, you can check the Git version
$ git --version git version 2.8.4 (Apple Git-73)