A book is a group of sheets of paper with printed information, or other material such as drawings, engravings or photographs, fastened together and enclosed in cover made of stronger paper or cardboard. A book can be either fiction (containing invented content, often narratives) or non-fiction (containing content intended to convey factual truth). Books may contain a single work or many different works, as well as non-textual elements such as illustrations and musical notation. Books are widely used for education and entertainment, and have a long history as a cultural artifact.
The concept of a book is so complex that it is impossible to capture in a single definition. However, there are some important features that distinguish books from other media and forms of communication. First, a book is portable. This feature might seem obvious, but it distinguishes books from, for example, posters fixed on walls and inscriptions on immovable entities. It also distinguishes books from inscribed records such as a diary, journal, memoir or scrapbook. Nevertheless, there is an undeniable connection between these and books: all are texts that can be transported over short or long distances and serve, to some degree, as resilient transmitters of knowledge and information.
As a cultural object, books are defined by the act of reading. The way that readers react to a text depends on many factors, including the genre of the text, the cultural and commercial transactions associated with its acquisition, the physical qualities of the book and its contents, the historical context in which it was produced, and so on. In addition, the reactions of individual readers to a particular text might be influenced by the fact that the book is part of a particular library or collection and can thus be interpreted as a product of its social and cultural context.
The physical structure of a book is also crucial to its character. As a result, the history of books has become an acknowledged academic discipline, with contributions from such fields as textual scholarship, codicology, bibliography, palaeography and art history. In particular, the study of book production and technology allows us to understand the nature of the book as a medium of textual interaction and how that has changed over time, not least in response to the gradual move to shorter texts and the emergence of new modes of storytelling in other media.
The latest development in book production is digital printing, which uses a continuous roll of paper rather than individual sheets and can print pages two at a time, rather than as separate signatures. This has made it possible to publish smaller runs, and to keep books in print even when they are not attracting enough sales to justify the cost of printing them in large numbers. It has also opened up the possibility of print-on-demand, in which a single book is printed as soon as it is ordered. This approach is being applied to some academic and scientific publications, particularly those with very specialised audiences.