Originally Posted by wallcraft
At Books on Board, and some other sites, Adobe Digital Editions means PDF with Adobe DRM. Adobe ePub means ePub with Adobe DRM.
If you have a choice, get the ePub. Reflowing PDFs can introduce artifacts, although the ebook is usually still readable. Since ePub is an intrinsically reflowable format it works better on a small screen.
Strange enough, in some instances I've found 2 versions of ePUB at Books on Board for the very same book, with different sizes. Any idea, what's this?