It's not that planets orbit the Sun and not the other way around, it's more accurate to say that both the Sun and the planets orbit around their common center of mass.

Here's a breakdown:

* Gravity: The Sun is much more massive than any of the planets. Gravity is a force of attraction between objects with mass. The more massive an object, the stronger its gravitational pull. This means the Sun's gravity exerts a much stronger pull on the planets than the planets' gravity exerts on the Sun.

* Center of Mass: While the Sun's gravity is much stronger, the planets still exert a gravitational pull on the Sun. This causes a slight wobble in the Sun's position. The point around which both the Sun and planets orbit is called the center of mass of the system.

* Relative Size: Because the Sun is so much more massive, the center of mass of the solar system lies very close to the Sun's center. This means that the planets appear to orbit around the Sun, even though technically they are both orbiting a common point.

Think of it like a seesaw: Imagine a seesaw with a very heavy adult on one side and a small child on the other. The fulcrum (the pivot point) will be closer to the adult, but both the adult and child will move up and down as the seesaw rocks. The Sun is like the heavy adult, and the planets are like the child.

In summary: The Sun and planets both orbit their common center of mass, but due to the Sun's much greater mass, this center is very close to the Sun's center, giving the appearance that the planets are orbiting the Sun.