Gravity is what pulls objects down to the Earth.
Here is the scientific definition for gravity: "the force that attracts a body toward the center of the earth, or toward any other physical body having mass. For most purposes Newton's laws of gravity apply, with minor modifications to take the general theory of relativity into account."
It works like this: Gravity makes an object go down. Like it is what makes people stand on earth and not fly all around Earth and space.
Space has flying objects like meteors, space objects that fly up there, and other things like those that go to space. If space had gravity we would have a whole bunch of planets, meteors, and even us (the whole earth with it) would fall down and probably would never stop falling because space doesn't have an end. But space has 0% gravity which causes us to not fall but since we are on the ring circling around the sun, earth doesn't go flying all around space.
An example is: Us. We're an example of gravity because we stick to the ground. Another example is: If there was a table with a rock on it, but the table moved, the rock would fall because of gravity and nothing would be in its way.
Glad to help! :)