Here's why:

* Stars produce their own light and heat through nuclear fusion in their core. The Sun generates energy by fusing hydrogen into helium.

* Planets orbit stars. The Earth and other planets in our solar system orbit the Sun.

* Stars are much larger and more massive than planets. The Sun is about 109 times wider than Earth and has about 333,000 times its mass.

So, the Sun is a giant, burning ball of gas that provides light and heat to our solar system.