CCTV (closed-circuit television) is a TV system in which signals are not publicly distributed but are monitored, primarily for surveillance and security purposes.

CCTV relies on strategic placement of cameras, and observation of the camera’s input on monitors somewhere. Because the cameras communicate with monitors and/or video recorders across private coaxial cable runs or wireless communication links, they gain the designation “closed-circuit” to indicate that access to their content is limited by design only to those able to see it.