It's basically the same. Both can give you STD's. Both are having sex for money. A pro of Porn is that they check for STD's often. A con is everyone is watching you. A pro for prostitution is the money is good, but you don't get to choose your clients.
Pornography does not spread disease; prostitution can. Porn, except for child porn, is created by consulting adults but no one is physically harmed by it. In prostitution, there is usually an increase in human trafficking / smuggling, use of under-age girls, violence of pimps and drug use by prostitutes. Prostitution also results in more abortions and violence. Porn does not.
Well, prostitution is illegal and porn is legal to buy as long as you're 18, so if you don't feel like going to jail, that's a major plus for porn. Prostitution gives you the actual experience, while porn is sort of just watching it happen on a screen. They're pretty different.