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. The division of work between the ghostwriter and the credited author varies a great deal. In some cases, a ghostwriter is hired to publish and edit a rough draft or a mostly completed manuscript. In this case, the outline, ideas and much of the language in the finished book or article are those of the credited author.
In other cases, a ghostwriter does most of the writing, using only concepts and stories provided by the credited author. In this case, a ghostwriter will do extensive research on the credited author or their subject area of expertise.