Here's why:

* Gravity: The sun is much more massive than all the planets in our solar system combined. This massive gravity creates a strong pull on the planets, causing them to orbit around it.

* Center of Mass: While planets orbit the sun, both the sun and planets are actually orbiting a common center of mass called the barycenter. Because the sun is so much more massive, the barycenter is usually located very close to the sun's center, giving the impression that the planets orbit the sun directly.

Let me know if you'd like to learn more about gravity or orbits!