Motion Detection, as the name suggests, is used to detect motion on security cameras. There are several types of motion detection used in selecting a digital video recorder (dvr).

Simple Motion Detection: If there is movement on a security camera, the selecting a digital video recorder (dvr) system is triggered to do an action, such as start recording video or trigger an alarm. Motion detection can be performed by the camera itself (e.g. ip camera), the DVR, or the NVR. Most systems provide motion detection that is not sensitive to small changes, so that (for example) small changes in ambient light or optical noise does not trigger motion detection.

Motion Detection by frame region: A more advanced form of motion detection that allows the user to set only a specific region of the screen (or frame) to trigger an action.

Advanced Motion Detection: Systems that analyze the video stream to determine if the motion is to trigger an action. For example, motion detection systems exist that can determine if a person turns around, leaves an object on the ground, or crosses an imaginary line.

In addition to triggering an action for the selecting a digital video recorder (dvr) system to take, the use of motion detection can reduce the amount of disk space needed to store video by not storing video when there is no motion.