* Sun: The Sun is a star, and it's significantly larger than the Moon. It's a giant ball of hot gas, and it's the largest object in our solar system.

* Moon: The Moon is a natural satellite that orbits the Earth. It's much smaller than the Sun.

* Stars: Stars are massive balls of hot gas that generate their own light and heat through nuclear fusion. While the Sun is our star, there are many stars in the universe that are much larger than our Sun.

In summary: The Sun is bigger than the Moon. The Sun is a star, and stars are much bigger than moons.