I have asked this question before, but never got much feedback so here goes again!

I am still confused - what is the difference between
Renova and Retin-A? I was prescribed
Renova, which many people have told me is "odd" because I am only 20 and
Renova is usually prescribed for older skin.
I am 80% clear, my main problem is skin tone and light red marks - that is when I was prescribed
Renova. However, I still DO have acne...will the
Renova help that?
Renova and Retin-A? What is the difference?