Rest and Motion are relative terms. What do you mean by this? Explain with an example.

State of motion and rest are relative in the sense that a body in motion with respect to one observer needs not to be in motion with respect to another and vice versa. for example you are sitting in a moving car with your friend then you are at rest with respect to your friend but if some stationary observer out side the car sees you then to him you will seem to be moving with the speed of car.