A system that uses video cameras to feed images to monitors in a centralised control room is known as a closed circuit television or CCTV. Security and surveillance are the main purposes for having CCTV cameras installed in key locations within an area.
Technology advancement has improved CCTV security systems from crude and noticeable surveillance cameras that capture colourless pictures to cameras that can follow motion and capture minute detail in full colour. In terms of data storing, the invention of digital video recorders (DVR) was a breakthrough. A security camera DVR can operate remotely, it is able to detect movement and it has an internal memory that saves captured footage taken over a long period of time. CCTV systems can also use internet protocol (IP) to send out images in digital form to specified networks. Wherever internet is available through a computer or mobile phone equipped with 3G, images that are being recorded by an IP security camera can be retrieved and viewed by the owner.
Institutions that involve monetary exchange like banks and casinos as well as public areas where many people congregate such as at airports, terminals and malls, are often secured by surveillance camera systems. Patrolling of passageways and offices can be done remotely from the security office of a building with the use of video surveillance systems, thus reducing the need for additional manpower. Security cameras can be used not only to monitor the inside of a building but to survey the outside areas like car parks and perimeter fences. Governments have also have a use for outdoor security cameras, to monitor traffic, identify violators of the law and track road mishaps. Residences can also be installed with home security systems to safeguard the property from break-ins and robbery.
The extensive usage of CCTV security has raised concerns regarding invasion of privacy. However, the installation of security cameras in public areas pose little threat to people's privacy whereas they contribute greatly to the prevention and investigation of crimes.