E-book, or electronic book, is a collection of digital (numerical) files that represent the words, and sometimes illustrations, of a book. An e-book is formatted so that, when viewed on a special handheld device or on a computer monitor, words and illustrations appear much as they would on a printed page. E-books are available for purchase via the Internet at Web sites of publishers and bookstores. Some libraries offer e-books that can be downloaded (transferred) over the Internet at no cost. Some periodicals are available as e-books. E-books first appeared in 1998.