CCTV means “closed-circuit television” and is commonly known as a video surveillance technology. “Closed-circuit” means broadcasts are limited (closed) to a selected group of monitors, unlike “regular” TV, which can be received and viewed by whoever sets up a reception device. CCTV networks are commonly employed to detect and deter criminal activities and record traffic infractions, but they also have other uses.
The first CCTV system was created in 1942 by German scientists seeking an effective way to track the trajectory of V2 rockets during World War II. American scientists would later use CCTV technology during atomic bomb testing because it allowed them to monitor activities like shock waves and blast effects without having people in harm’s way.