Access Control systems are designed to permit the free flow of authorised movement into any premises, property or business, whilst denying entry to unwanted visitors and staff.
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.
An intercom (intercommunication device), talkback or doorphone is a stand-alone voice communications system for use within a building or small collection of buildings, functioning independently of the public telephone network.