This document provides an introduction to Git and common branching models. It begins by defining Git as a distributed revision control system created by Linus Torvalds for Linux kernel development. It then discusses why Git is useful, how it is distributed and optimized for merging, and some key Git concepts like commits, branches, and the local repository structure. The document also outlines common Git commands, workflows like centralized, feature branching, Gitflow and GitHub flow, and how pull requests enable collaboration. It concludes by listing additional Git learning resources.