So you know how there are award shows for movies where they give out prizes to the best movies and actors? Well, the Golden Raspberry Awards are kind of like the opposite of that. They give out awards to the movies (or actors) that people didn't really like or that were just really, really bad.
One of these awards is called the "Worst Picture" award. This means that out of all the movies that came out that year, the Golden Raspberry people thought that one particular movie was the worst. Like, it was really, really bad. And they give the movie a special award for being so bad.
It's kind of like getting an award for being the worst at something. But instead of feeling bad about it, people actually kind of like it. It's almost like a joke -- like, "wow, this movie was so bad that it actually won an award for being bad!" Sometimes the actors or directors of the movie even show up to the Golden Raspberry Awards to accept the award and make jokes about how bad their movie was.
So yeah, that's the basic idea of the Golden Raspberry Award for Worst Picture. It's an award for the worst movie of the year, and people think it's funny.