title_body: Question about vocabulary used on itunes paid ibook application form
upvoted_answer: You've pretty much sussed out "frontlist"--the older titles, by comparison, are all "backlist". And yes, digital rights are similar to copyright. Basically (and IANAL), the author has copyright to the created work, and can then assign/give/sell some or all of those rights to other people. So "digital rights" means that you either have copyright, or the author has assigned you the right to publish digitally. So it's not quite the same as copyright, but it does mean "yes, I'm allowed to do this".
  
  Active print catalog simply means "how many print titles do you have in current rotation?" If you're doing exclusively ebooks, that number will be zero.