A book is a series of pages assembled for easy portability and reading, as well as the composition contained in it. The book's most common modern form is that of a codex volume consisting of rectangular paper pages bound on one side, with a heavier cover and spine, so that it can fan open for reading. Books have taken other forms, such as scrolls, leaves on a string, or strips tied together; and the pages have been of parchment, vellum, papyrus, bamboo slips, palm leaves, silk, wood, and other materials.
The contents of books are also called books, as are other compositions of that length. For instance, Aristotle's Physics, the constituent sections of the Bible, and even the Egyptian Book of the Dead are called books independently of their physical form. Conversely, some long literary compositions are divided into books of varying sizes, which typically do not correspond to physically bound units. This tradition derives from ancient scroll formats, where long works needed several scrolls. Where very long books in codex format still need to be physically divided, the term volume is now normally used. Books may be distributed in electronic form as e-books and other formats. A UNESCO conference in 1964 attempted to define a book for library purposes as "a non-periodical printed publication of at least forty-nine pages, exclusive of cover pages". A single sheet within a codex book is a leaf, and each side of a leaf is a page. Writing or images can be printed or drawn on a book's pages.
English "bōc", which in turn comes from the Germanic root " bōk-", cognate to "beech". Similarly, in Slavic languages "буква" is cognate with "beech". In Russian and in Serbian and Macedonian, the word "букварь" or "буквар" 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. Similarly, the Latin word codex, meaning a book in the modern sense, originally meant "block of wood".
History
Antiquity
When writing systems were created in ancient civilizations, a variety of objects, such as stone, clay, tree bark, metal sheets, and bones, were used for writing; these are studied in epigraphy.
Tablet
A tablet is a physically robust writing medium, suitable for casual transport and writing. Clay tablets were flattened and mostly dry pieces of clay that could be easily carried, and impressed with a stylus. They were used as a writing medium, especially for writing in cuneiform, throughout the Bronze Age and well into the Iron Age. Wax tablets were pieces of wood covered in a thick enough coating of wax to record the impressions of a stylus. They 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 is a possible precursor of modern bound books. The etymology of the word codex also suggests that it may have developed from wooden wax tablets.