How does gravity work?

Gravity is a force pulling together all matter (which is anything you can physically touch). The more matter, the more gravity, so things that have a lot of matter such as planets and moons and stars pull more strongly. Mass is how we measure the amount of matter in something.

Well gravity is something that keeps us people from floating off into space its just like if you sit a apple on a table some times it roles right and some times it doesn't but say their was no gravity that apple will float right up into space