I've included a link from a regional board thread about this very topic. Once again, Porn Star, is one of those often used terms in the hobby, that's open to wide interpretation. If you're not on freeones.com or a site like it, you're not a ps.

There are in fact a few true "porn stars" who will, on occasion, escort.   Those true stars command $$$$ prices at least.    However, for purposes of TER profiles, I generally consider "porn star" to be roughly translated to mean:

"At least once in my life i have been paid a third of a typical one hour escort fee to get filmed being savagely fucked in the ass without a condom by some tattooed maggot, immediately after which, without washing him up, I sucked him off until he jizzed all over my face, and while the producers never made any money off of it nor could you buy a copy of the video if you wanted to, you (or someday, my children), may be able to find a brief clip of the experience on some free website like PornHub if you really look hard enough."

Not worth a visit IMHO, for so many reasons

Just some thoughts.
If you are an unknown, but you have the lead role in a film, you are the star of that film.

"How would you like to star in my new movie?"

But outside of that one film. to be  known as a star, you need some name recognition.
Paris Hilton could pass that star-fame test although no one would accuse her of being a film star.

If you were one of many people in a porn film, but not the lead, I don't think you are a porn star by some definition, but to your close friends and lovers you may be indeed be a pron star to them

As Einstein says, everything is relative.

When some providers quote different rates for GFE and Porn Star, I don't think they're mentioning film, They're probably trying to hint at Greek although I would be more likely to think it had to do with all-out effort and intensity (a girl friend would make sweet love, a porn star will ravish you).

So it's about as clear and accurate as any marketing. Good reviews are more useful.

And, unrelated to all the above, in this digital age, can we really call movies "films" anymore?