Git is a version control system that allows tracking changes to files and coordinating work among contributors. It provides commands to initialize a repository, add and commit changes, clone or pull from existing repositories, and branch and merge codebases. Git uses a three-stage process where files can be modified, staged for commit, and permanently committed. Branching enables parallel development while merging integrates changes. Additional useful commands include diff to compare changes, log to view history, and blame to see who last modified each line of a file.