I imagine it as separating a branch from the rest of the tree and attaching it to a new base commit ("rebase"). Naturally you need to apply all diffs (interpret

I imagine it as separating a branch from the rest of the tree and attaching it to a new base commit ("rebase"). Naturally you need to apply all diffs (interpreting commits as diffs here) from the original branch to the new base commit. So you re-based it.