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Spy-Cam - Closed-circuit televisionClosed-circuit television (CCTV) is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint, or mesh wireless links. Though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that may need monitoring such as banks, casinos, airports, military installations, and convenience stores. Videotelephony is seldom called "CCTV" but the use of video in distance education, where it is an important tool, is often so called.[1][2]In industrial plants, CCTV equipment may 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 may operate continuously or only as required to monitor a particular event. A more advanced form of CCTV, utilizing digital video recorders (DVRs), provides recording for possibly many years, with a variety of quality and performance options and extra features (such as motion-detection and email alerts). More recently, decentralized IP-based CCTV cameras, some equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation. Surveillance of the public using CCTV is particularly common in many areas around the world including the United Kingdom, where there are reportedly more cameras per person than in any other country in the world.[3] There and elsewhere, its increasing use has triggered a debate about security versus privacy.A traffic camera is a video camera which observes vehicular traffic on a road. Typically, these are put along major roads such as highways, freeways, motorways, autoroutes and expressways, as well as arterial roads, and are connected with optical fibers buried alongside or even under the road, with electrical power either provided by mains power in urban areas, or via solar panels or another alternate power source which provides consistent imagery without the threat of a power outage during inclement conditions.A monitoring center receives the live video in real time, and serves as a dispatcher if there is a traffic collision or some other disruptive incident or road safety issue.Traffic cameras are a major part of most intelligent transportation systems. They are especially valuable in tunnels, where safety equipment can be activated remotely based upon information provided by the cameras and other sensors. On surface roads, they are typically mounted on high poles or masts, sometimes along with street lights. On arterial roads, they are often mounted on traffic light poles at intersections, where problems are most likely to occur.Traffic cameras are distinct from road safety cameras, which are put in specific places to enforce rules of the road. Those cameras take still photos in a much higher image resolution upon a trigger, whereas traffic cameras are simply for observation and constantly take lower-resolution video, often in full motion. Many transmit in the legacy analog NTSC and PAL formats, depending on location. Some have a compass built in which displays the cardinal direction at which the camera is aimed, though many providers also provide a reference image of a shot with the cardinal direction.Traffic monitoringMany cities and motorway networks have extensive traffic-monitoring systems, using closed-circuit television to detect congestion and notice accidents.[36] Many of these cameras however, are owned by private companies and transmit data to drivers' GPS systems.