Git is a version control program used for managing files in software development across development teams. Git stores project files in repositories. The repository contains the files themselves, and the history of all changes to the files. Using Git commands, developers update their repository to include other developer’s contributions, make changes to their own repository and push those changes to other repositories.
Git is open source software, meaning it is free to use and anyone can contribute to the code base. It was initially created by the developer of Linux, Linus Torvalds, to manage development of the Linux kernel. It is still used for that purpose today.
Alternatives to Git
Git is our version control system of choice, beating out contenders such as Subversion and Mercurial. While Git is the most popular version control software in the world, the choice is not a clear cut one. Git is more flexible than either alternative, but is more complex and harder to get to grips with initially. All three competitors are used to manage notable projects, just a few are noted below:
These and other version control systems are compared in a Wikipedia article.
You can read more about Git at these resources: