An electronic book (variously: e-book, eBook, e-Book, ebook, digital book, or even e-edition) is a book-length publication in digital form, consisting of text, images, or both, readable on computers or other electronic devices.
Although sometimes defined as “an electronic version of a printed book”, many e-books exist without any printed equivalent. Commercially produced and sold e-books are usually intended to be read on dedicated e-readers, however, almost any sophisticated electronic device that features a controllable viewing screen, including computers, tabletsand smartphones can also be used to read e-books.
E-book reading is increasing in the US; by 2014 28% of adults had read an e-book, compared to 23% in 2013. This is increasing because 50% of Americans by 2014 had a dedicated device, either an e-reader or a tablet, compared to 30% owning such a device by the end of 2013.