A book is a medium for recording information in the form of writing or images. Modern books are typically in codex format, composed of many pages that are bound together and protected by a cover; they were preceded by several earlier formats, including the scroll and the tablet. The book publishing process is the series of steps involved in their creation and dissemination. As a conceptual object, a book refers to a written work of substantial length, which may be distributed either physically or digitally as an ebook. These works can be broadly classified into fiction (containing invented content, often narratives) and non-fiction (containing content intended as factual truth). A physical book may not contain such a work: for example, it may contain only drawings, engravings, photographs, puzzles, or removable content like paper dolls. It may also be left empty for personal use, as in the case of account books, appointment books, autograph books, notebooks, diaries and sketchbooks. Books are sold at both regular stores and specialized bookstores, as well as online for delivery, and can be borrowed from libraries. The reception of books has led to a number of social consequences, including censorship. 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. Source: Wikipedia (en)