Gravity is a force that pulls you down towards the center of an object. When you jump up, you go “down”. Gravity also makes large object such as Earth round because Gravity pulls from every direction toward the center of the Earth. Every object in the universe including you, have gravity, it is just extremely weak to even pull or overcome anything. Gravity also keeps our planets and moons in orbit. Even the ISS. The closer you are to the object, the faster you have to go to rotate it. That’s why Mercury takes 88 days to make a full rotation and 2,000 years for Pluto to make a full orbit.