Hill jumping is when you ride your bike, skateboard, or another cool ride down a hill really fast and then jump off a ramp or jump at the end of the hill to go airborne. Imagine you're riding down a big slope like the one at the playground, and at the bottom, there is a ramp that helps you go super high into the air. That's what hill jumping is all about!
To do hill jumping, you need to be very careful and wear safety gear like a helmet and knee pads. You also need to make sure you have a ramp or jump set up at the end of the hill to land safely.
Hill jumping takes practice, courage, and most importantly, safety precautions. So start small and work your way up to big jumps, and always have an adult supervising you to help keep you safe.