Hah, I didn’t think it was that bad. Not an expert myself, but:
SQL is a language for managing databases, like we would have here. PHP gets the data, and configures it into a webpage. HTML is basic markup that browsers can read. CSS and JavaScript in this context would mostly be for visuals, effects and some other interactions.
Again, I’m sort of guessing; but most of this stuff is standard, and I’d be surprised if this site wasn’t built with PHP at least.