Types of editorial review
Substantive Reviews
Also called "content reviews" (but not to be confused with content appraisals, which I do not profess to do), this is the first step in the editing process, the step when we look primarily at the overall concept, organization and logic, readability and clarity, flow and transitions, and continuity.
Copyedits
This is the step that most people think of when they contemplate what an editor does. By the time we start a copyedit, your text should be in place and well on its way to publication. During a copyedit, I check and correct (or query when necessary) reading level and vocabulary selection, spelling, punctuation, grammar, agreement and parallelism, consistency, and logic. If a substantive review was not done previously (or if issues identified during the substantive review were not adequately addressed), some of those issues might be incorporated, as well.
Proofs
Proofreading, or proofing, is one of the last stages in the editing process and should not be done until the text is nearly ready for typesetting. A proof of the manuscript text would include a final read through of the text with a critical look at previous decisions on punctuation, grammar, and word choice. A proof of the typeset pages would include evaluation and correction of text alignment, word division, line breaks and page breaks, page citations, header and footer formatting, and general page appearance.