That's a great question! You're talking about gravity.

Here's the breakdown:

* Gravity is a fundamental force of nature. It's what keeps us on the ground, holds the moon in orbit around Earth, and keeps the planets in orbit around the sun.

* It's a force of attraction between any two objects with mass. The more massive an object is, the stronger its gravitational pull.

* The strength of gravity also depends on the distance between the objects. The closer they are, the stronger the gravitational attraction.

So, even though we might not feel it all the time, gravity is constantly at work, attracting every object in the universe to every other object!