See this slide deck for an overview of what git does, and how it represents changes to a codebase.
See https://www.datacamp.com/tutorial/github-and-git-tutorial-for-beginners#basic-commands-befor
See https://docs.replit.com/replit-workspace/using-git-on-replit/use-gui
See https://docs.github.com/en/repositories/working-with-files/managing-files