iBooks is an application created by Apple for both iOS and OS X to enable viewing of PDF, Epub and .iBooks format files, typically electronic books.
iBooks is an application created by Apple for both iOS and OS X to for viewing PDFs and EPUBs as well as .ibooks files.
The app can be downloaded on iOS from the App Store and preinstalled on OS X since Mavericks.
This tag is for questions relating to both the iOS and OS X versions of the iBooks app.
For questions regarding iBooks Author, use ibooks-author.