Where is the line between proofreading and editing?

Proofreading corrects the surface of your writing: spelling, grammar, punctuation, and consistency. Your words, meaning, and argument stay exactly as you wrote them.

Editing does everything proofreading does, then goes further. It changes sentence structure, tone, and flow where it helps, and leaves comments explaining any substantive edit.

Both come back as tracked changes, so you accept or reject every change line by line.