Closed-circuit television (CCTV) is the use of video cameras to transmit signals to a specific place into a limited set of monitors. Although it may employ point to point (P2P), point to multipoint, or mesh wireless links, but its signal is not transmitted openly as compared to broadcast television. The term CCTV only applies to video cameras used for surveillance purposes that required constant monitoring such as banks, casinos, airports, military installations, and convenience stores where CCTV systems can operate continuously.
Digital Video Recorders (DVRs), which is a more advance form of CCTV provides recording for years, with a variety of quality and performance options and extra features (such as motion-detection and email alerts). some decentralized IP-based CCTV cameras are equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation.