What is Copy Editing vs Proofreading?

Copy editing and proofreading are distinct stages of the editorial process that are often confused. Copy editing occurs earlier and is more substantive: it addresses sentence structure, word choice, consistency, flow, tone, factual accuracy, and adherence to style guidelines. Proofreading occurs later, after layout or formatting, and focuses on surface errors: typos, misspellings, punctuation mistakes, formatting inconsistencies, and broken links. A copy editor might restructure a paragraph for clarity, while a proofreader would catch a missing comma in that paragraph. Both are essential, and conflating them typically means one or both are done poorly.