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 clay 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). These kinds of works can be broadly classified into fiction (containing invented content, often narratives) and non-fiction (containing content intended as factual truth). But a physical book may not contain a written work: for example, it may contain only drawings, engravings, photographs, sheet music, puzzles, or removable content like paper dolls.

The modern book industry has seen several major changes due to new technologies, including ebooks and audiobooks (recordings of books being read aloud). Awareness of the needs of print-disabled people has led to a rise in formats designed for greater accessibility such as braille printing and large-print editions.

Google Books estimated in 2010 that approximately 130 million total unique books had been published. The book publishing process is the series of steps involved in book creation and dissemination. Books are sold at both regular stores and specialized bookstores, as well as online (for delivery), and can be borrowed from libraries or public bookcases. The reception of books has led to a number of social consequences, including censorship.

Books are sometimes contrasted with periodical literature, such as newspapers or magazines, where new editions are published according to a regular schedule. Related items, also broadly categorized as "books", are left empty for personal use: as in the case of account books, appointment books, autograph books, notebooks, diaries and sketchbooks.

The word book comes from the Old English bōc, which in turn likely comes from the Germanic root *bōk-, cognate to "beech". In Slavic languages like Russian, Bulgarian, Macedonian буква bukva—"letter" is cognate with "beech". In Russian, Serbian and Macedonian, the word букварь (bukvar') or буквар (bukvar) refers to a primary school textbook that helps young children master the techniques of reading and writing. It is thus conjectured that the earliest Indo-European writings may have been carved on beech wood. The Latin word codex, meaning a book in the modern sense (bound and with separate leaves), originally meant "block of wood".

An avid reader or collector of books is a bibliophile, or colloquially a "bookworm".

In its modern incarnation, a book is typically composed of many pages (commonly of paper, parchment, or vellum) that are bound together along one edge and protected by a cover. By extension, book refers to a physical book's written, printed, or graphic contents. A single part or division of a longer written work may also be called a book, especially for some works composed in antiquity: each part of Aristotle's Physics, for example, is a book.