Have you ever used git cherry-pick? Git rebase is if you were loop over each commit (bottom to top) and run `git cherry-pick` on each commit separately.

If you haven't used git cherry-pick, then it is basically a shortcut for `git show $REF | git apply -`, where the short cut is the simplest form of using git, you have a patch (via git show) and you want to apply it to your local checkout.

> "apply a commit on another branch". What does that actually mean?

Calculate the difference between the commit and its parent, and repeat that change against another branch.

So, like git log of your work over 10 days, git show each commit individually, then apply each patch that generates against the latest code.

Of course it's defined, even git knows what it means because that's what cherry-pick does.

So cherry-pick is actually merge, and rebase is actually cherry-pick?

Everything is merge.

No, cherry-pick is cherry-pick. Rebase is a composite action which includes one or more cherry-picks.