Ok kiddo, have you ever heard jazz music before? It's a really cool style of music that is kind of like a big game of musical pretend. Musicians who play jazz take turns making up their own parts while still playing together like a team.
Free jazz is like jazz but with even more imagination and creative freedom. It's like the musicians are playing a game of pretend where there aren't any rules, so they can make up whatever sounds they want to with their instruments.
This type of music doesn't have a specific melody or rhythm that the musicians have to follow. Instead, they get to improvise and play whatever they feel like in the moment, which can sound really crazy and different each time they play.
Sometimes people think that free jazz kind of sounds like a big group of musicians playing different songs at the exact same time, but that's ok because it's all part of the fun and creative freedom of the music.
So in summary, free jazz is a type of jazz music where musicians get to play whatever they want and use their imaginations to create unique and unpredictable sounds.