How does the gravity related to the humans

I think most people know it is by the gravity, so what is gravity? How it works? The gravity which is a kind of energy to made the objects be gathered to the center. It is produced by the earth. So that's why we can see the rocks on the mount was go down not go up and the rivers brought the mud from the higher place to a lower place ( the river also will be affected by the gravity). Furthermore, maybe you don't even know, how will determine the power of gravity. Actually, it was determined by many aspects, including the mass of the planet. So we know earth is a huge planet and it has higher gravity. To be imagined, that's why the spaceman will lose the control of gravity on some other small planets.