Book
A book is a structured presentation of recorded information, primarily verbal and graphical, through a medium. Originally physical, electronic books and audiobooks are now existent. Physical books are objects that contain printed material, mostly of writing and images. Modern books are typically composed of many pages bound together and protected by a cover, what is known as the codex format; older formats include the scroll and the tablet.
As a conceptual object, a book often refers to a written work of substantial length by one or more authors, which may also be distributed digitally as an electronic book (ebook).