During the editing and proofreading stage you will correct any remaining errors.
Proofreading is the process of looking for and correcting errors in your work. Proofreading refers to the last stage of the editing process, centering on certain mistakes including misspellings and grammar, spelling, formating and punctuation errors. You should proofread only after you have culminated all of your other editing revisions.
Editing is the task performed once you have finished your first draft.