Whatever really happened, Newton realized that some force must be acting on falling objects like apples because otherwise they would not start moving from rest.
Newton also realized that the moon would fly off away from Earth in a straight line tangent to its orbit if some force was not causing it to fall toward the Earth. The moon is only a projectile circling around the Earth under the attraction of Gravity.
I called this force "gravity" and determined that gravitational forces exist between all objects.
He compared the straight path of the apple to the curved path of a fired cannonball. He wondered what would happen if the cannonball went faster and faster, and realized it would eventually “fall” around the curve of the Earth forever, and never hit the ground.
So that is gravity!
Einstein's new theory of Gravity explains a number of phenomena that would violate Newton's theory but what's important is that God gave us the world and we should be thankful everyday and we have to take care of the things that He gave us.
And one more thing. After Newton discovered gravity, Einstein developed a whole new idea about gravity.