See your books on all your devices
With iCloud, your books, PDFs, collections, highlights, notes, and bookmarks appear automatically on your Mac and your iOS devices where you’re signed in with the same Apple ID. iCloud also remembers which page you’re on.
See all the books you purchased in the iBooks Store
On your Mac: In your iBooks library, click Sort By, then choose Show iCloud Books. If you see Hide iCloud Books, the books you purchased are already being displayed.
On your iOS device: In your iBooks library, tap a collection (such as All Books) to see the list of your collections, then make sure Hide iCloud Books isn’t turned on.
See collections, highlights, notes, and bookmarks
On your Mac: Choose iBooks > Preferences, click General, then select “Sync bookmarks, highlights, and collections across devices.”
On your iOS device: Go to Settings > iBooks, then turn on “Sync Bookmarks and Notes” and “Sync Collections.”
See the books and PDFs you added to iBooks
On your Mac: Choose Apple menu > System Preferences, then click iCloud. Click Options next to iCloud Drive (make sure iCloud Drive is turned on), then select iBooks.
On your iOS device: Go to Settings > [your name] > iCloud (or Settings > iCloud), turn on iCloud Drive, then turn on iBooks (iOS 9.3 or later).
You can hide books you purchased in the iBooks Store that you don’t want to see on your devices. Hidden books don’t appear in your library or in iCloud. If you have Family Sharing set up, your family members can’t see or download hidden books.