Proofreaders read transcripts or proof type setups to detect and mark for correction any grammatical, typographical, or compositional errors. They ensure the accuracy and consistency of tables, graphs, photos, page numbers, and any other elements used in a document. This position title excludes workers whose primary duty is editing copy, but includes proofreaders of Braille.
Editors review, rewrite, and edit the work of writers. They also may do original writing. An editor’s responsibilities vary with the employer and type and level of editorial position held. Editorial duties may include planning the content of books, journals, magazines, and other general-interest publications. Editors also review story ideas proposed by staff and freelance writers then decide what material will appeal to readers. They review and edit drafts of books and articles, offer comments to improve the work, and suggest possible titles. In addition, they may oversee the production of publications. In the book-publishing industry, an editor’s primary responsibility is to review proposals for books and decide whether to buy the publication rights from the author. Most editors begin work as writers. Those who are particularly adept at identifying stories, recognizing writing talent, and interacting with writers, may be interested in editing jobs.
Source: Bureau of Labor Statistics, Occupational Outlook Handbook