Okay kiddo, I'm going to explain what a bridge exercise is in a very simple way that you'll understand.
So, imagine you're lying down on your back like you're about to go to sleep. Now, lift up your hips and bum off the ground so that only your feet and shoulders are touching the floor.
Kinda like a bridge that you cross over a river, right? That's why it's called a bridge exercise!
Now, hold that position for a few seconds and then lower yourself back down to the floor. See? That's a bridge exercise - lifting your hips up and down while only your feet and shoulders are touching the ground.
It's a great exercise for your bum muscles and your core. And it's a lot of fun too! Try it out yourself and see how strong you can be like a bridge.