What is altitude?

Altitude is how high something is above the ground or sea level.

Imagine you're playing on a slide at the park. If you're standing right at the bottom of the slide, you’re at altitude zero, like being on the first floor of a building. But if you climb all the way to the top of the slide and look down, you’re now higher up, that’s your altitude. It's like counting steps: each step you take up makes your altitude bigger.

Think about climbing stairs in a tall building. When you're on the first floor, you're at a low altitude. As you go up one floor, two floors, three floors, your altitude increases just like that. By the time you reach the top floor, you're way up high!

When you’re on a plane and it takes off, you feel the plane rising into the sky. That’s increasing altitude too! You start near the ground, then you go higher and higher until you're floating above the clouds, just like climbing stairs but much faster.

So whether you're going up a slide or flying in a plane, altitude is just how high you are from where you started.