Zip
compressed version of other file types
printable document
PRC/Mobi – ebook file
best for Kindle, Kindle Fire and Mobipocket
MP3 – audio
plays on all music players
iPod-iTunes (AAC) – audio
best for iPad, iPhone, iPod and iTunes users, as well as Android users with Akimbo or similar app
EPUB – ebook file
best for iPad, iPhone, iPod, Sony Reader, and Nook