Well, kiddo, you know how sometimes when you're playing in a swimming pool or at the beach, a really big wave comes along and catches you off guard? Well, sometimes in the ocean there can be even bigger waves, called freak waves. Like, really, really big.
Freak waves happen when a whole bunch of different waves are coming together at the same time, like they're having a big party in the ocean. When they all clash together, it can make one super-duper big wave. Sort of like when you mix all the colors together when you're painting and you get a big blob of color that's harder to control.
These big waves can be really dangerous for boats and ships, because they can toss them around really hard and even cause them to tip over. But scientists are still studying these waves to try and learn more about how they work, so maybe one day we'll know how to predict them better and keep people safe from them.