What is gravity?

Gravitation or  gravity is the force of attraction between any two bodies. We know that all the objects in the universe attract each other.But in most cases,the force of attraction is too weak to be noticed.This is because of the large distance of separation between the two bodies.Gravity’s range is infinite but the effect becomes weaker as objects move away.Force of attraction between  planets and sun is an example for such cases..The gravitational force of attraction was first observed by Sir Isaac Newton.
Example:
If ball is thrown upwards, it reaches a certain height and falls downwards because of the gravity of the earth. Here,gravitational force of earth is the  force of attraction exerted by earth towards its centre on a body lying on or near the surface of the earth. 
Regards.