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.
An electronic motion detector contains an optical, microwave, or acoustic sensor, and in many cases a transmitter for illumination. However, a passive sensor senses a signature only from the moving object via emission or reflection, i.e., it can be emitted by the object, or by some ambient emitter such as the sun or a radio station of sufficient strength.