Well, both are legal in Denmark, but i can see a difference between the 2. Not saying one is better than the other, but this may make a difference in someone elses eyes.
A prostitute sells herself (or himself) to the people she has sex with.
A pornstar sells her/himself to have sex with anotehr pornstar, hence no-one is paying to fuck anyone, people are paying all participants to fuck eachther, so all the fuckers are proffesionals, and none of them are costumers, the cosumers are wankers.
Then theres the borderline cases, where some pornstars have figured, that they can make more money if they cast their fans as the male pornstars, and let them pay, to fuck them on film, which they then makes money off of.
theres also amateur porn where real couples film themsleves having "real" sex, and then sell it.
I think both things should be (reamain the the case of Denmark wher ei live) legal. The prostitutes should be required to have a certificate, in order for it to be legal, which would basicly require that they paid taxes of whatever they amde and had regular STD tests, and if they we're infected needed to be cured to get them renewed.
This would help fight forced prostitution (sex slaves) and maybe help fight STD infected whores.
if the prostitute is seen as a criminal, they will stand ina bad possition, where they can't seke help from the law, and is easier abused. This will not stop prostituion the slightest, it'll just make life worse for teh prostitutes, who are supposed to be the victims in teh first place.
If they're legal, they have the law on their side, and can sefely call the cops if someone tried to hurt them, they can keep off dark streets in bad neigborhoods, and work at bigegr, safer and better organized whore-houses.
I don't think anyone have or should have the right to buy sex, but peopel should have teh right to sell their bodies (sex) to whoever wants to buy it.