Aliens vs. Predator (1990) was a run of comics involving the titular characters from the Alien and Predator franchises. It was an original story that served as a crossover for the franchises and added a bunch of new lore to both franchises. With that said, that new lore is not considered canon to those franchises. Aliens vs. Predator is technically a distinct third franchise that just takes inspiration from those two franchises.

Aliens vs. Predator: Prey (1994) was a novelization of the comic book series. It was a direct adaptation of the comics, taking every major aspect of the story and just making it into a different type of media. It is effectively the same as the comics, beat by beat.

The film Alien vs. Predator (2004), on the other hand, was an original story. But while it differed from the comics in many ways, it clearly took inspiration from them. It almost seemed as if it took as much as possible from the comics but changed just as much as was necessary to make sure they would not have to pay royalties or anything and could technically call it an “original” story.