Mass and gravity is one of the most confusing terms among physics students. Along with mass and gravity another key concept which needs to be mentioned along with these is weight. Many people often confuse weight with mass and mass with weight. To be in frank, mass is the term used to denote ‘ how much stuff is inside’ while weight tells us about the gravitational interaction between the objects with mass . Mass is constant at any point, even if an object is at moon, the mass remains constant but weight changes with change in gravitational force. Gravity is termed as the attractive force acting between two objects . Earth attracts every object towards its centre. It is because of this force all objects are able to stay on earth surface . But another contradictory fact is that the weakest force in the universe is the weak gravitational force.