Balloon (aeronautics)

Imagine holding a balloon in your hand. You blow air into it and tie a knot at the end. The balloon gets bigger and bigger as you blow more air into it.

Now, imagine that the balloon is very big and you can sit inside it. You blow air into it until it's so big that it starts to float in the air.

This is called a balloon in aeronautics. The big balloon is filled with a gas that is lighter than air, called helium, which makes it rise up into the sky.

People can ride in the balloon's basket that is attached to the bottom of the balloon. The pilot controls the balloon by letting some of the helium gas out or pulling on different ropes to make the balloon go up, down or sideways.

It's like you're flying in the sky, but instead of a plane, you're in a big, colorful balloon!