TOPIC: PMP vs CAPM?

I recently passed my CAPM exam and have turned my attention next to the PMP. I still have a ways to go in terms of getting experience hours, but in the meantime I'd like to understand what are the substantive differences in terms of content between the CAPM and PMP exams? I understand that the PMP exam is a little harder because it asks you more situational questions, but are there also particular topics that the PMP exam covers that the CAPM does not?