Closed circuit television, more commonly referred to as CCTV, is most widely known for its use as part of a security and surveillance system. CCTV involves the use of video cameras which transmit a signal to a specific place, on a limited set of monitors. This is unlike broadcast television, from which the signal can be picked up by any receiver that is correctly tuned.

CCTV is most often used in association with surveillance of specific areas, for example banks, casinos, airports and retail stores; however, there are a number of more unique applications for which CCTV is also beneficial including, monitoring traffic on a bridge, installed on public transit to minimize vandalism, and use by the stage manager of a theatre to view obscured areas of the set. A CCTV system can be tailored to the individual needs of the user, and may be as simple or complex as required to achieve the surveillance required.