A hang glider is like a giant kite that you can ride on! It's a really big piece of fabric (like a big blanket) that is attached to a frame. You lay down on the frame and hold onto a bar that's in front of you, and then you run really fast off a hill or a mountain.
The wind catches the fabric and lifts you up into the air! You steer the hang glider by moving your body around on the frame and tilting the bar. It's like riding a bike in the sky!
Hang gliders are really cool, but they can also be a little scary. You have to make sure you're always flying in safe conditions and that you have the right training and equipment. But if you do it right, it can be an amazing adventure!