Closed-circuit television

Closed-circuit television (CCTV), also known as video surveillance, is the use of <a href="/facts/Closed-circuit_television_camera/qtUnLpMg">closed-circuit television cameras</a> to transmit a signal to a specific place on a limited set of monitors. It differs from <a href="/facts/Broadcast_television/BT0FfFcy">broadcast television</a> in that the signal is not openly transmitted, though it may employ <a href="/facts/Point-to-point_(telecommunications)/RmGgN1Pj">point-to-point</a>, <a href="/facts/Point-to-multipoint_communication/6xWWhgdn">point-to-multipoint</a> (P2MP), or <a href="/facts/Mesh_networking/XnVSy5rK">mesh</a> wired or <a href="/facts/Wireless/GfDoFwfo">wireless links</a>. Even though almost all video cameras fit this definition, the term is most often applied to those used for <a href="/facts/Surveillance/hJhvWdSJ">surveillance</a> in areas that require additional security or ongoing monitoring (<a href="/facts/Videotelephony/Ya9TMFQD">videotelephony</a> is seldom called "CCTV").
The deployment of this technology has facilitated significant growth in state surveillance, a substantial rise in the methods of advanced social monitoring and control, and a host of crime prevention measures throughout the world. Though surveillance of the public using CCTV is common in many areas around the world, video surveillance has generated significant debate about balancing its use with individuals' <a href="/facts/Right_to_privacy/q9jY2KWz">right to privacy</a> even when in public.
In <a href="/facts/Factory/GPIW0snN">industrial plants</a>, CCTV equipment may be used to observe parts of a process from a central <a href="/facts/Control_room/CLfAR5zC">control room</a>, especially if the environments observed are dangerous or inaccessible to humans. CCTV systems may operate continuously or only as required to monitor a particular event. A more advanced form of CCTV, using <a href="/facts/Digital_video_recorder/g8V6BsU5">digital video recorders</a> (DVRs), provides recording for possibly many years, with a variety of quality and performance options and extra features (such as <a href="/facts/Motion_detection/SXwDdwrx">motion detection</a> and <a href="/facts/Email/6pD9GLtI">email</a> alerts). More recently, decentralized <a href="/facts/IP_camera/45X46Bgf">IP cameras</a>, perhaps equipped with megapixel sensors, support recording directly to <a href="/facts/Network-attached_storage/ABVjy8Tn">network-attached storage</a> devices or internal flash for stand-alone operation.

Closed-circuit television open-in-new

Closed-circuit television