Mobi — reflowable content, meaning that a Mobi reader can optimize text for a particular display device. (tps1.com)
ePub — reflowable content, meaning that an ePub reader can optimize text for a particular display device. (tps1.com)
About EPUB: EPUB is designed for reflowable content, meaning that an EPUB reader can optimize text for a particular display device. (ebookconverter.com)