The word book comes from Old English “bōc” which comes from Germanic root “*bōk-”, cognate to beech. Similarly, in Slavic languages (e.g. Russian and Bulgarian “буква” (bukva)—”letter”) is cognate to “beech”. It is thus conjectured that the earliest Indo-European writings may have been carved on beech wood. Similarly, the Latin word codex, meaning a book in the modern sense (bound and with separate leaves), originally meant “block of wood.”
 History of books
Main article: History of books
Sumerian language cuneiform script clay tablet, 2400–2200 BCWhen writing systems were invented in ancient civilizations, nearly everything that could be written upon—stone, clay, tree bark, metal sheets—was used for writing. Alphabetic writing emerged in Egypt around 1800 BC. The Ancient Egyptians would often times write on papyrus, a plant grown along the Nile River. At first the words were not separated from each other (scriptura continua) and there was no punctuation. Texts were written from right to left, left to right, and even so that alternate lines read in opposite directions. The technical term for this type of writing is ‘boustrophedon,’ which means literally ‘ox-turning’ for the way a farmer drives an ox to plough his fields.
Main article: Scroll
Egyptian papyrus showing the god Osiris and the weighing of the heart.Papyrus, a thick paper-like material made by weaving the stems of the papyrus plant, then pounding the woven sheet with a hammer-like tool, was used for writing in Ancient Egypt, perhaps as early as the First Dynasty, although the first evidence is from the account books of King Neferirkare Kakai of the Fifth Dynasty (about 2400 BC). Papyrus sheets were glued together to form a scroll. Tree bark such as lime (Latin liber, from there also library) and other materials were also used.
According to Herodotus (History 5:58), the Phoenicians brought writing and papyrus to Greece around the tenth or ninth century BC. The Greek word for papyrus as writing material (biblion) and book (biblos) come from the Phoenician port town Byblos, through which papyrus was exported to Greece. From Greeks we have also the word tome (Greek: τόμος) which originally meant a slice or piece and from there it became to denote “a roll of papyrus”. Tomus was used by the Latins with exactly the same meaning as volumen (see also below the explanation by Isidore of Seville).
Whether made from papyrus, parchment, or paper in East Asia, scrolls were the dominant form of book in the Hellenistic, Roman, Chinese and Hebrew cultures. The more modern codex book format form took over the Roman world by late antiquity, but the scroll format persisted much longer in Asia.
Main article: Codex
Woman holding a book (or wax tablets) in the form of the codex. Wall painting from Pompeii, before 79 AD.Papyrus scrolls were still dominant in the first century AD, as witnessed by the findings in Pompeii. The first written mention of the codex as a form of book is from Martial, in his Apophoreta CLXXXIV at the end of the century, where he praises its compactness. However the codex never gained much popularity in the pagan Hellenistic world, and only within the Christian community did it gain widespread use. This change happened gradually during the third and fourth centuries, and the reasons for adopting the codex form of the book are several: the format is more economical, as both sides of the writing material can be used; and it is portable, searchable, and easy to conceal. The Christian authors may also have wanted to distinguish their writings from the pagan texts written on scrolls.
A Chinese bamboo bookWax tablets were the normal writing material in schools, in accounting, and for taking notes. They had the advantage of being reusable: the wax could be melted, and reformed into a blank. The custom of binding several wax tablets together (Roman pugillares) is a possible precursor for modern books (i.e. codex). The etymology of the word codex (block of wood) also suggests that it may have developed from wooden wax tablets.
In the 5th century, Isidore of Seville explained the relation between codex, book and scroll in his Etymologiae (VI.13): “A codex is composed of many books; a book is of one scroll. It is called codex by way of metaphor from the trunks (codex) of trees or vines, as if it were a wooden stock, because it contains in itself a multitude of books, as it were of branches.”
 Middle Ages