EPub is the newer standard and is supported by the Apple iBooks app, but Apple only supports it's own FairPlay DRM wrapper used to encrypt the ePub files to protect the books from being copied or read on unauthorised devices. Most other (non-Apple) eBook stores sell ePub books encrypted with Adobe's Adept DRM wrapper, which you can't read with the iBooks app (although certain other eBook apps do support the Adobe DRM system) Mobi is for other reader systems (I believe the Kindle uses this format) and is not supported by the iBooks app. I expect there are other iPhone apps that support mobi files.
Sep 21, 2018 - iBooks becomes Apple Books in iOS 12, and while the reading. MacOS Mac App Updates Media Creation Networking Opinion Problem Solving. To get: how many books of each format your library contains (I currently have. I settled on the ePub and PDF formats and use Calibre on my Mac to strip. Jan 15, 2011 - They are downloaded in ePub format and I have eventually. Cannot open it is formatted incorrectly or is not a format that ibooks can open. EPub DRM Removal quickly and easily remove Adobe ebook ADEPT DRM protection. It supports ePub/PDF drm ebook that was opened in Adobe digital editions, create new nodrm file without DRM limitation. User can view ePub ebook on iPad, NOOK, Sony Reader or other device, convert to mobi format to read in Kindle ereader, convert to PDF format to print Digital Edition ebook.