The sun doesn't actually move through the sky. It's the Earth that's rotating on its axis, which makes it *appear* as though the sun is moving across the sky.

Here's a simple breakdown:

* Earth's Rotation: Our planet spins on its axis, completing one full rotation every 24 hours. This rotation is what causes day and night.

* Sun's Position: The sun stays relatively still, but as the Earth turns, we see the sun in different positions in the sky throughout the day.

So, the apparent movement of the sun across the sky is just an illusion caused by the Earth's rotation.