A broken CD or DVD or other type of optical disc is a serious problem and one that will likely lead to loss of information stored on this media. A broken optical disc refers to a disc that has split into two or more pieces or perhaps a disc simply missing one piece.
A motion detector is a device that detects moving objects, particularly people. A motion detector is often integrated as a component of a system that automatically performs a task or alerts a user of motion in an area.
Best Answer: stormgal.. thats the irony that makes yahoo answers so fun...revel my friend....revel... a PIR is basically a form of motion detector, it triggers the camera to take a picture if something passes in front of the sensor.