Piston

Okay, so do you know what a straw is? It's a skinny tube that you can suck liquid through. Well, imagine a straw that is really long and thick, and instead of sucking liquid, it moves up and down all by itself. That's kind of what a piston is, but instead of being made out of plastic like a straw, it's made out of metal.

Pistons are usually found inside engines, like in cars or airplanes. They move up and down in a long, skinny tube called a cylinder. The piston is connected to a rod that moves it up and down, and that rod is connected to a bunch of other parts that help the engine run.

When fuel is burned in the engine, it makes a small explosion that pushes the piston up. Then, the piston comes back down because of the force of gravity. This up and down motion is what makes the engine run and powers the car or airplane forward.

So basically, a piston is a metal tube that moves up and down inside another tube, and helps engines work by turning fuel into energy.