Absolute ear, absolute pitch and perfect pitch are all the same thing. It's the ability to identify a note, interval, key etc. without an external source.
Perfect pitch is something one is born with (so begins the nature vs. nurture argument) and cannot be "learned." Most musicians have what is called relative pitch which can be learned and studied through various ear training exercises.
Don't feel bad about not having perfect pitch. I have a couple of friends that say it's a curse.
Best wishes,