First install Brew which is a tool for installing software on your mac
brew install git
sudo apt-get install git
Open a terminal and run:
git --version
Adds a heads up display so that you can easily see what you're working on in Git, eg. which branch you are on, and how many commits ahead of master it is. As a bonus - it makes your command line look awesome!
Allow you to autofill the end of your git commands in the command line using the TAB key on your keyboard.