A book is a set of written, printed, illustrated, or blank sheets, made of ink, paper, parchment, or other materials, fastened together to hinge at one side. A single sheet within a book is a leaf, and each side of a leaf is a page. A set of text-filled or illustrated pages produced in electronic format is known as an electronic book, or e-book. The body of all written works including books is literature. In novels and sometimes other types of books (for example, biographies), a book may be divided into several large sections. Source.