file format – device information
EPUB – The EPUB format is supported by most non-Amazon devices including the Nook and the iPad (using iBooks). If you have an Android device, you can install an app that will let you view EPUB files. It is also possible to view EPUB files on a PC by downloading an appropriate application.
MOBI – The MOBI format is supported on all Amazon Kindle devices.
AZW3 – A file with the AZW3 extension is an eBook created in the Kindle Format 8 , Amazon’s successor to the AZW format. It is used as the download format for later Amazon eBooks. AZW3 files can be previewed with Kindle Previewer.