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, stores, and other areas where security is needed.
Cameras have also been installed on public transport in the hope of deterring crime, and in mobile police surveillance vehicles, often with automatic number plate recognition, and a network of APNI-linked cameras is used to manage London's congestion charging zone.
Closed-circuit television was used as a form of pay-per-view theatre television for sports such as professional boxing and professional wrestling.
Boxing telecasts were broadcast live to a select number of venues, mostly theaters, where viewers paid for tickets to watch the fight live.
The development of reel-to-reel media enabled the recording of surveillance footage.
These systems required magnetic tapes to be changed manually, which was a time consuming, expensive and unreliable process, with the operator having to manually thread the tape from the tape reel through the recorder onto an empty take-up reel.