Inertia is the act of trying to move a stationary object in a steady state and a moving object in the same direction without moving an external force. Inertia is two types of inertia and motion inertia. As we have seen from our daily life experience , to force a heavy object to move from a stationary state to a moving state and from a moving state, we have to apply a higher quality force than a lighter object, that is , more difficult. So inertia depends on the mass of the object and mass is actually a measure of the inertia of the object. In the case of both types of inertia, the greater the mass of the object, the greater its inertia.