* Earth's Rotation: Our planet spins on its axis like a top. It takes about 24 hours for the Earth to complete one full rotation. As the Earth turns, different parts of the planet face the sun, creating the illusion of the sun moving across the sky.
* Earth's Orbit: The Earth orbits the sun in a slightly elliptical path. This orbit, combined with the tilt of Earth's axis, causes the sun's apparent path in the sky to vary throughout the year. This is why we have different seasons.
In summary: It's our perspective from Earth's spinning and orbiting that makes the sun appear to move across the sky. It's actually our planet that's in motion.
