Motion is the change in position of an object with time. An object is said to be in motion if it changes its position relative to a fixed point. For example, a moving car, a running person, or a falling ball are all in motion. To understand and describe motion, we need to measure the distance an object travels. Distance is the length of the path between two points and is usually measured in units like meters or kilometers. Different tools are used to measure distance depending on the situation, such as a ruler for short lengths or an odometer for longer distances. Accurate measurement of distance is important in science, transport, and everyday life to understand how far and how fast things move.