This won't be an elaborated post on all that's new in FR9. That will need more than one post as some of the new features are substantial. Indeed, I will at least do a part 2 post with link for where you can find far more on what's new than you may readily find, in FR resources you might otherwise miss.
Instead in this part-1 post I just want to point out what's new (improved or fixed), and indicate what aspects apply to users only of the FR Cloud feature, and what aspects apply to users of the on-prem version as well. (I will also briefly explain the difference between those, for folks not aware.)
I'll also point to info on how to update FR (if you may not do it often), and finally discuss what resources do exist about FR 9, which again I will elaborate on in part 2.