A book is both a usually portable physical object and the body of immaterial representations or intellectual object whose material signs—written or drawn lines or other two-dimensional media—the physical object contains or houses.

As a physical object, a book is a stack of usually rectangular pages (made of papyrus, parchment, vellum, or paper) oriented with one side (either left or right, depending on the direction in which one reads a script) tied, sewn, or otherwise fixed together and then bound to the flexible spine of a protective cover of heavier, relatively inflexible material so that, when the opened front cover has received a massy enough stack of sheets, the book can lie flat.[1] The technical term for this physical arrangement is codex (in the plural, codices). In the history of hand-held physical supports for extended written compositions or records, the codex replaces its immediate predecessor, the scroll. A single sheet in a codex is a leaf, and each side of a leaf is a page.

As an intellectual object, a book is prototypically a composition of such great length that it takes a considerable investment of time to compose and a still considerable, though not so extensive, investment of time to read. This sense of book has a restricted and an unrestricted sense. In the restricted sense, a book is a self-sufficient section or part of a longer composition, a usage that reflects the fact that, in antiquity, long works had to be written on several scrolls, and each scroll had to be identified by the book it contained. So, for instance, each part of Aristotle's Physics is called a book, as of course the Bible encompasses many different books. In the unrestricted sense, a book is the compositional whole of which such sections, whether called books or chapters or parts, are parts.

But the intellectual content in a physical book need not be a composition, or can be called a book. Books can consist only of drawings, engravings, or photographs, or such things as crossword puzzles or cut-out dolls. In a physical book the pages can be left blank or can feature an abstract set of lines as support for on-going entries, i.e., an account book, an appointment book, a log book, an autograph book, a notebook, a diary or day book, or a sketch book. Some physical books are made with pages thick and sturdy enough to support other physical objects, like a scrapbook or photograph album. Books may be distributed in electronic form as e-books and other formats.

Although in ordinary academic parlance a monograph is understood to be a specialist academic work, rather than a reference work on a single scholarly subject, in library and information science monograph denotes more broadly any non-serial publication complete in one volume (book) or a finite number of volumes (even a novel like Proust's seven-volume In Search of Lost Time), in contrast to serial publications like a magazine, journal, or newspaper. An avid reader or collector of books or a book lover is a bibliophile or colloquially, "bookworm". A shop where books are bought and sold is a bookshop or bookstore. Books are also sold elsewhere. Books can also be borrowed from libraries. Google has estimated that as of 2010, approximately 130,000,000 distinct titles had been published.[2] In some wealthier nations, the sale of printed books has decreased because of the use of e-books,[3] though sales of e-books declined in the first half of 2015.[4]


The word book comes from Old English "bōc", which in turn comes from the Germanic root "*bōk-", cognate to "beech".[5] Similarly, in Slavic languages (for example, Russian, Bulgarian, Macedonian) "буква" (bukva—"letter") is cognate with "beech". In Russian and in Serbian and Macedonian, the word "букварь" (bukvar') or "буквар" (bukvar) refers specifically 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.[6] Similarly, the Latin word codex, meaning a book in the modern sense (bound and with separate leaves), originally meant "block of wood".

Other Languages
Afrikaans: Boek
Alemannisch: Buch
አማርኛ: መጽሐፍ
العربية: كتاب
aragonés: Libro
armãneashti: Carti
asturianu: Llibru
Atikamekw: Masinahikan
Avañe'ẽ: Kuatiañe'ẽ
Aymar aru: Panka
azərbaycanca: Kitab
تۆرکجه: کیتاب
bamanankan: Gafɛ
বাংলা: বই
Bân-lâm-gú: Chheh
башҡортса: Китап
беларуская: Кніга
беларуская (тарашкевіца)‎: Кніга
भोजपुरी: किताब
български: Книга
Boarisch: Buach
bosanski: Knjiga
brezhoneg: Levr
буряад: Ном (бэшэг)
català: Llibre
Чӑвашла: Кĕнеке
čeština: Kniha
chiShona: Bhuku
Cymraeg: Llyfr
dansk: Bog
Deitsch: Buch
Deutsch: Buch
डोटेली: पुस्तक
eesti: Raamat
Ελληνικά: Βιβλίο
español: Libro
Esperanto: Libro
euskara: Liburu
فارسی: کتاب
français: Livre (document)
Gaeilge: Leabhar
Gaelg: Lioar
Gàidhlig: Leabhar
galego: Libro
ГӀалгӀай: Джей
Hausa: Littafi
հայերեն: Գիրք
हिन्दी: पुस्तक
hrvatski: Knjiga
Ido: Libro
Ilokano: Libro
Bahasa Indonesia: Buku
interlingua: Libro
Interlingue: Libre
ᐃᓄᒃᑎᑐᑦ/inuktitut: ᕿᒥᕐᕈᐊᑦ/qimirruat
Ирон: Чиныг
isiXhosa: Incwadi
isiZulu: Incwadi
íslenska: Bók
italiano: Libro
עברית: ספר
Basa Jawa: Buku
Kabɩyɛ: Takayaɣ
ಕನ್ನಡ: ಪುಸ್ತಕ
ქართული: წიგნი
қазақша: Кітап
Kinyarwanda: Igitabo
Kiswahili: Kitabu
коми: Небӧг
Kreyòl ayisyen: Liv (pou li)
kurdî: Pirtûk
Кыргызча: Китеп
ລາວ: ປຶ້ມ
Latina: Liber
latviešu: Grāmata
Lëtzebuergesch: Buch
лезги: Улуб
lietuvių: Knyga
Limburgs: Book
lingála: Búku
Livvinkarjala: Kirju
la .lojban.: cukta
lumbaart: Liber
magyar: Könyv
македонски: Книга
Malagasy: Boky
മലയാളം: പുസ്തകം
मराठी: पुस्तक
مصرى: كتاب
Bahasa Melayu: Buku
Mìng-dĕ̤ng-ngṳ̄: Cṳ̆
Mirandés: Libro
монгол: Ном
မြန်မာဘာသာ: စာအုပ်
Nāhuatl: Amoxtli
Nederlands: Boek (document)
Nedersaksies: Boek (literetuur)
नेपाली: पुस्तक
नेपाल भाषा: सफू
Napulitano: Libbro
нохчийн: Жайна
norsk: Bok
norsk nynorsk: Bok
occitan: Libre
олык марий: Книга
oʻzbekcha/ўзбекча: Kitob
ਪੰਜਾਬੀ: ਕਿਤਾਬ
पालि: पोत्थकं
پنجابی: کتاب
Patois: Buk
Tok Pisin: Buk
Plattdüütsch: Book
polski: Książka
português: Livro
Ripoarisch: Boch (z lääse)
română: Carte
Runa Simi: Patara qhilqa
русиньскый: Книга
русский: Книга
саха тыла: Кинигэ
Scots: Beuk
Setswana: Buka
shqip: Libri
sicilianu: Libbru
සිංහල: පොත
Simple English: Book
سنڌي: ڪتاب
SiSwati: Íncwadzí
slovenčina: Kniha
slovenščina: Knjiga
Soomaaliga: Buug
کوردی: کتێب
српски / srpski: Књига
srpskohrvatski / српскохрватски: Knjiga
Basa Sunda: Buku
suomi: Kirja
svenska: Bok
Tagalog: Aklat
Taqbaylit: Adlis
татарча/tatarça: Китап
తెలుగు: పుస్తకము
тоҷикӣ: Китоб
Türkçe: Kitap
тыва дыл: Ном
українська: Книга
اردو: کتاب
Vahcuengh: Saw
vèneto: Łibro
vepsän kel’: Kirj
Tiếng Việt: Sách
Volapük: Buk
Winaray: Libro
吴语: 图书
ייִדיש: בוך
Yorùbá: Ìwé
Zazaki: Kıtabi
žemaitėška: Kninga
中文: 图书