Git is a free & open source, distributed version control system designed to handle everything from small to very large projects with speed and efficiency.
Every Git clone is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on network access or a central server. Branching and merging are fast and easy to do.
GitHub is a great way to collaborate with others. Fork, send pull requests and manage all your public and private git repositories. It also provides an offsite backup ensuring that your project is safe.
Here are some of my posts related to git: