Proofreading (also proof-reading) is the reading of a galley proof or computer monitor to detect and correct production-errors of text or art. Proofreaders are expected to be consistently accurate by default because they occupy the last stage of typographic production before publication. wikipedia.org

Developmental editing is a form of writing support that comes into play before or during the production of a publishable manuscript, especially in the area of non-fiction writing. wikipedia.org

An electronic book is a book-length publication in digital form, consisting of text, images, or both, readable on computers or other electronic devices. wikipedia.org

A ghostwriter is a professional writer who is paid to write books, articles, stories, reports, or other texts that are officially credited to another person. wikipedia.org