Developmental editing vs line editing vs copyediting vs proofreading: what’s the difference? 

If you’re confused by editing terms, you’re in excellent company. The simplest way to think about it is this: developmental editing fixes the big picture; line editing improves how the writing reads; copyediting corrects consistency and correctness; proofreading catches final typos before publication.

The difference in plain English 

Developmental editing looks at the structure: argument, chapter order, logic, gaps, repetition, pacing, and whether the book delivers what it promises.
Line editing looks at the writing itself: clarity, rhythm, tone, flow, and how each paragraph lands.
Copyediting checks correctness and consistency: grammar, spelling, punctuation, facts (sometimes), style choices, and “are you calling it Chapter 3 or Three?”
Proofreading is the final polish: typos, formatting glitches, missing words, and small errors after everything else is finished.

Which one do you need first? 

A good rule: start with what changes the most.
If you might delete, move, or rewrite sections, start with developmental editing (or do a strong developmental self-edit first). If the structure is solid but the writing feels clunky or unclear, line editing helps. If the writing is strong but you need correctness and consistency, copyediting. Proofreading comes last.

Common mistake 

Getting copyedited too early. It’s painful (and expensive) to polish sentences you later cut.

A gentle next step

If you want a calm, step-by-step way to work out what your manuscript needs, Course 1: Editing Foundations walks you through it in the right order.