I do not know what kind of book you are asking about, but in order to create a book, there must be text, pictures, photos, etc. that will serve as the manuscript. The manuscript must be attractive enough to make people want to read it.
To achieve this, beautiful pictures and photos must be placed on the cover, the title of the book must be thoughtful, and the text must be rewritten many times to make it more interesting.
This kind of work is a collaborative effort of many people, including the author, editors at the publisher, illustrators, photographers, and designers.
In order to make a book, a section of text must first be typed, checked for errors, and if any are found, they must be corrected. This is called proofreading. Then, pictures and photographs are printed, and the printed paper is folded and bound to form a book. This is the work of the printing company and the bookbinding company.
In this way, many people share the various tasks involved in the production of a book.
Even for a single comic book, many people are involved in the process of making it.