An e-book is, quoting wikipedia, ” the digital media equivalent of a conventional printed book.” The main advantage of this format is it´s hypertextuability. Thanks to this, the text has key words, linked to other texts, and these have other key words connecting them to other texts, and this can go on indefinitely. 
Also, the amount of space an e-book requires is minimum. One of these devices can store more than 500 books, a complete bookshelf. E-books can also be switched into spoken books, making them accessable to sufferers of inpaired sight. The distribution and copying of an e-book is cheap, easy and fast. Furthermore, a backup device is kept, meaning that an e-book is dificult to eliminate once produced. Also, the ease of its production leaves more room for experimentation by authors and editors
Above all, the publishing of an e-book does not require paper nor ink nor all the machinery that normal books need, making them more compatible with environmental care.
