An object is said to be in motion if it is moving. For example, a car driving down the road is in motion. This is because its position is changing relative to its surroundings.
However, there is a difference between being at rest and being stationary. Stationary objects are not moving, but they are not necessarily at rest. For example, a boat floating down a river is stationary. This is because its position is not changing relative to the water. However, it is not at rest because the water is moving.
In order for an object to be truly at rest, it must not be moving relative to any of its surroundings. For example, a car parked on the side of the road is at rest. This is because its position is not changing relative to the road or the surrounding buildings.
