Expert Git
Everything so far has been about using Git well. This section is about understanding it, and about the tools that only make sense once you do.
None of it is required for daily work. It is here because at some point you will meet a colleague who says "just cherry-pick the tree object" or "use includeIf", and because knowing what a commit really is turns most remaining Git mysteries into obvious consequences.
Before you start: the rest of the course, or at least Section 2, Section 6 and Section 12.