Definition: 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-book readers, however, almost any sophisticated electronic device that features a controllable viewing screen, including computers, tablet computers, and smartphones can also be used to read e-books.
Advantages: Thousands of titles can be stored on mobile devises; websites can provide translations unavailable for printed books; e-books can be viewed in low-light and can incorporate motion, sound, enlarged or changed fonts; searching for specific words or concepts can easily be accomplished. Although the mobile devise may be expensive, the cost of an individual e-book is generally less than for a printed version and many older titles are in the public domain and thus free.
Challenges: Techniques may be used to restrict what the user may do with an e-book. It may not be possible to transfer ownership of an e-book to another person and some devices can track readers and reading habits, restrict printing, or arbitrarily modify or remove reading material.