Here's why:

* Staying in place: A reference point is a stationary object that doesn't move.

* Detecting motion: We use reference points to determine if something else is moving. If the object we're observing changes position relative to the reference point, we know it's moving.

Examples:

* Trees on the side of the road: When you're driving, trees seem to move backward, indicating your car is moving forward.

* A fixed star in the night sky: We use stars as reference points to see how planets and the moon appear to move across the sky.

* The background of a video: In a video, objects that are stationary in the background allow us to see if an object in the foreground is moving.