Here's why:

* Motion is relative: An object can be in motion relative to one observer but at rest relative to another. For example, a passenger sitting in a moving train is at rest relative to the train but in motion relative to someone standing on the ground.

* Reference point provides context: The reference point gives us a basis for comparison. It tells us what is considered "stationary" or "not moving."

* Frames of reference: A frame of reference is a coordinate system used to describe the position and motion of an object. It can be any object or point that is considered stationary for the purpose of observation.

Examples of reference points:

* The ground

* A stationary building

* A moving vehicle

* Another object

In conclusion, motion is always relative to a chosen reference point or frame of reference. Without a reference point, it's impossible to determine if something is actually moving or not.