I would say the editing phase, as I have done a lot of writing and multiple people around me refer it as that, but the revising stage also covers editing, which doesn't make much sense. I guess that it depends on what your class taught you. Sorry if this doesn't help you, but my best answer would be the editing, since it covers going back through a paper to check for errors. Do you know what the exact definition of "editing" and "revising" is and could you get back to me with that?
