Video Security or CCTV
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. 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”.
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 DVRs (Digital Video Recorders), 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 cameras, some equipped with megapixel sensors, support recording directly to NVR (Network Video Recorder) – 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. In recent years, the use of body worn video cameras has been introduced as a new form of surveillance.
An Internet protocol camera, or IP camera, is a type of digital video camera commonly employed for surveillance, and which, unlike analog closed circuit television (CCTV) cameras, can send and receive data via a computer network and the Internet. Although most cameras that do this are webcams, the term “IP camera” or “netcam” is usually applied only to those used for surveillance. The first centralized IP camera was Axis Neteye 200, released in 1996 by Axis Communications.
There are two kinds of IP cameras:
Centralized IP cameras, which require a central Network Video Recorder(NVR) to handle the recording, video and alarm management.
Decentralized IP cameras, which do not require a central Network Video
Recorder (NVR), as the cameras have recording function built-in and can thus record directly to any standard storage media, such as SD cards, NAS (network attached storage) or a PC/Server.