Uniform motion occurs when an object travels equal distances in equal intervals of time along a straight line. In uniform motion, the speed of the object remains constant throughout its journey. An example is a train moving at a constant speed of 60 km/h on a straight track. Non-uniform motion, on the other hand, occurs when an object travels unequal distances in equal intervals of time, or vice-versa, or when its direction changes. Its speed is not constant. An example is a car moving in heavy traffic, where it frequently speeds up, slows down, or stops.