Here's why:

* Sun: The Sun is a giant ball of hot gas that produces its own light and heat through nuclear fusion. This process releases enormous amounts of energy, causing the Sun to glow.

* Earth: Earth reflects sunlight. It does not produce its own light. The light we see on Earth is sunlight that has bounced off the surface of the Earth, including the oceans, land, and clouds.

Let me know if you have other questions!