Git is a version control system that allows tracking changes to files. It uses a local repository that is synced with a remote repository, like GitHub. The document discusses the Git workflow involving a working directory, staging area, and local/remote repositories. It also summarizes key Git commands like add, commit, branch, merge, clone, pull, push, and status/log. Finally, it mentions Hacktoberfest and GitHub's student developer pack for getting free stuff by contributing to open source projects.