Git is a version control system that allows tracking changes to files. It works by taking snapshots of files and storing reference hashes locally. There are three main stages - modified, staged, and committed. Git recommends following a workflow that involves making changes on a development branch, testing, merging to master, and pushing to a remote repository. Common commands include git add to stage changes, git commit to commit them locally, and git push to push to a remote. Branches allow parallel development, and git merge is used to integrate branches.