Though actually, the job title people say is copy-editor (or copy editor): someone whose work is to make the words in a book, newspaper, or magazine correct and ready to print. Copy-edit is usually the verb for what that person does. They do more than catch spelling. They check names, dates, and facts; they tidy grammar; they make the writing follow the house style; they cut what is unclear. A proofreader (校對) mostly hunts typos on the almost-final page. A copy-editor still has time to reshape a sentence. The 'copy' here is the text itself — old newspaper talk for the words to be set in type — not 'a photocopy'. You will meet both spellings: copy-edit and copyedit.