CCTV stands for closed-circuit television and is commonly known as video surveillance. “Closed-circuit” means broadcasts are usually transmitted to a limited (closed) number of monitors, unlike “regular” TV, which is broadcast to the public at large. CCTV networks are commonly used to detect and deter criminal activities, and record traffic infractions, but they have other uses.
CCTV technology was first developed in 1942 by German scientists to monitor the launch of V2 rockets. It was later used by American scientists during the testing of the atomic bomb.