Line or Word Editing
This is editing that begins with an agreement that the document we start with is basically organized the way it should be.
So, line or word editing does not address overall conceptual or structural questions, but focuses on making sure that the words and sentences do the best possible job of communicating the writer's ideas. This could include corrections or suggested changes to grammar, punctuation, word choice, sentence structure or length and paragraph breaks.
This kind of editing also tends to get into matters of clarity, which could involve cutting redundant statements, resolving apparent contradictions and simplifying the language. Word editing can include changes in style to achieve the right level of formality or informality or to capture the "voice" the writer feels is right for the piece.