Git is a program which can be used through terminal to manage repositories for storing files and saving different versions of a project. When used in conjunction with GitHub it gives you the ability to save your work at any point in time and note why a save was made. This can help you keep track of your personal project or work in collaboration with a team.
Git can be a very important tool because it helps us save versions of our work and track our progress. This means that if something isn't working or you change your mind on the direction of the project you always have a repository that allows you to return to a previous version of the file(s) without haveing to edit the master copy or completely start over.