Tools·intermediate
GitHub
Where your Git repositories live online. The social network for code.
Git is the local tool. GitHub is the website where you store your repositories online.
You git push your local commits to GitHub. From there, collaborators git pull them down. Open-source projects live on GitHub. Job applications often link to your GitHub. It's where most of software development happens in public.
GitHub adds features on top of Git: pull requests for reviewing proposed changes, issues for tracking bugs, actions for running code automatically when things change. You'll use a subset of these in Arc III.