Closed circuit television (CCTV) also known as video surveillance is the use of video cameras to transmit a signal to a specific place on a limited set of monitors. It differs from open television in that the signal is not transmitted openly, although it can use point-to-point (P2P), point-to-multipoint (P2MP) or mesh or wireless links. Although almost all video cameras conform to this definition, the term is applied more frequently to those used for surveillance in areas that may need monitoring such as bars, banks, casinos, schools, hotels, airports, hospitals, restaurants, facilities military, convenience stores and other areas where security is needed. Although Video telephony is rarely called "CCTV" an exception is the use of video in distance education, where it is an important tool.
Public surveillance through CCTV is common in many areas of the world. In recent years, the use of body video cameras has been introduced as a new form of surveillance, often used in law enforcement, with cameras placed on the chest or head of a police officer. Video surveillance has generated a significant debate on how to balance its use with the right of individuals to privacy, even when in public.
In industrial plants CCTV equipment can be used to observe parts of a process from a central control room, for example, when the environment is not suitable for humans. CCTV systems can operate continuously or only as needed to monitor a particular event. A more advanced form of CCTV, which uses digital video recorders (DVR), provides recordings for possibly many years, with a variety of quality and performance options and additional features (such as motion detection and email alerts). More recently, decentralized IP cameras, some equipped with megapixel sensors, support recording directly on storage devices connected to the network or internal flash for a completely independent operation. There are around 350 million surveillance cameras around the world as of 2016. About 65% of these cameras are installed in Asia. The growth of CCTV has been slowing down in recent years.