I just found a (rather old) post from Cisco Press which tells you all you need about the electronic books, their formats, their various readers (Mac, iPhone/iPad, Kindle, Nook, Android, PC, etc.) in a few English paragraphs. I recommend you go and read (and bookmark, too) eBook Formats FAQ.
Kindle, iPad and paper: A detail comparison
Kindle and iPad are two contenders trying to support the idea of reading on a technology gadget. It is said that this is actually as easy to read as real printed paper. So, Keith Peters tried a comparison of their displays using a microscope. The results are really impressive as you can see in Kindle…