Relative motion refers to the movement of an object as observed from a particular frame of reference. For example, if you are sitting in a train moving at a constant speed, you might see another train on an adjacent track moving in the opposite direction. To you, that train appears to be moving faster than it actually is, because you are also in motion. The concept of relative motion is essential in physics, as it helps to understand how different observers perceive the movement of objects. For instance, a car traveling at 60 miles per hour appears to be moving quickly to a stationary observer, but to a passenger inside the car, it feels like they are at rest.