.. toctree:: :maxdepth: 1 :titlesonly: git commandlinegit remotes conflicts moregit
Git is a source code management system, designed to support collaboration.
GitHub is a web-based service that hosts Git projects, including Django itself: https://github.com/django/django.
Git is a quite remarkable tool. It's fearsomely complex, but you can start using it effectively without needing to know very much about it. All you really need is to be familiar with some basic operations.
The key idea in Git is that it's distributed. If you're not already familiar with version control systems, then explaining why this is important will only introduce distinctions and complications that you don't need to worry about, so that's the last thing I will say on the subject.