Is a book only a collection of glue, pulp and ink? An impression from mater sets of characters accurately composed into words, lines and pages? Is it a visual representation of letters on a computer, smart phone or reader? The words you listen to from an audio file?
Depending on whom you ask, it may be any or all of those things. The traditional reader may well scoff at anything but the physical form; 'They may call them books, but this is a REAL book' as they hold it above their heads. Some folks will say 'anything that has words and has a nearly plausible plot' is a book.
But all will ask me 'why would you even ask that?'.
Because the history of books, and printing in particular, is a combination of the story of the men and materials used as well as the development of the art (Bringhurst, 3). For nearly five centuries, the printed word has been the preserver of knowledge and the medium of literature. And until the digital age and the explosion of the Internet, the physical book was the greatest means of communication of through time.
But with the digital age, the information gathered in a complete narrative could be called a "website", "blog", an "electronic or ebook", a "podcast", or a book. These narratives can impart information, give knowledge, entertain and allows us to offer the information that we want to share to be heard. And with the various ways it can be defined and the inclusion any or all of these methods used in the education system, we need as a community and a profession answer serious questions about what we define as literate.