I think we’re at the very beginning of a huge transformation that will change how we think about books. Thanks to new devices and publishing platforms, books are becoming more interactive and multimedia. One form this is taking is the "enhanced" ebook. To understand the enhanced versions, let’s start with normal ebooks.
“Normal” ebooks are essentially digital versions of regular books that are usually read on devices like the Kindle, iPad and Nook. For most of their history, ebooks have been quite similar to their paper-based counterparts in terms of content. But this is starting to change and for the first time, we’re starting to see “enhanced” ebooks.
Enhanced ebooks are essentially multimedia books. They are available on devices like iPad and Kindle Fire, which are designed for watching video and listening to audio. This makes it possible for a book to have the written word accompanied by audio, video and interactive content. A couple of examples:
The Art of Explanation

Resonate
Another example is Nancy Duarte’s book Resonate, which she calls a "multi-touch" book. Resonate is wonderful example because it uses the full menu of enhanced ebook options, from audio and video, to interactive quizzes, graphs and behind-the-scenes content. I've seen no better example of enhanced ebooks than Resonate. Again, why read about famous speeches when you can watch or listen to them in an enhanced ebook?

Enhanced ebooks are just getting started. I expect to see more innovation in this area in coming years. Imagine a science, music or art textbook in school that is “enhanced” to include interactive lessons along with audio and video. The potential is tremendous.