Okay, sweetie, so let's talk about the porn industry and STIs. STIs are short for sexually transmitted infections which are sicknesses that people can get when they have sex with someone who already has the infection.
So, people in the porn industry can also get STIs because they have sex with a lot of different people. That's why before they can start making movies, they need to get checked by a doctor to see if they have any STIs. It's kind of like going to the doctor for a check-up to make sure you are healthy.
They do this because they don't want to spread any STIs to the other people in the movies or to their personal partners. It's important to make sure everyone is healthy and safe!
If someone does have an STI, they can't work in the industry until they get treated and are no longer infected. This is because they could spread the infection to others during a film shoot.
So in short, people in the porn industry need to make sure they are healthy and STI free before they can make movies, so they don't spread or catch any infections.