Motion detection
Motion detection is a camera or software function that flags change in the scene, either by comparing pixels between frames or by detecting and tracking an object that moves. Pixel-based motion detection fires on shadows, rain and lighting; track-based motion detection fires only on a confirmed person, vehicle or object.
The pixel approach is what most recorders and cameras ship with, and it is why so many alerts are ignored: a tree in the wind and a person at the gate look the same to it.
The track approach runs an object detector first and reports motion only for something it recognizes. It costs more compute and produces alerts a person can act on.
On Camzify motion detection is track-based and comes with every stream instance at no charge, along with camera tampering detection. It is the baseline that the other detections build on.