Closed-circuit television, 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.
A fire alarm system has a number of devices working in unison to detect and warn people through visual and audio appliances when smoke, fire, carbon monoxide or other emergencies are present. Alarms can be either motorised bells or wall mountable sounders or horns.
An intrusion detection system is a device or software application that monitors a network or systems for malicious activity or policy violations. Any intrusion activity or violation is typically reported either to an administrator or collected centrally using an event management and security information system.
In the fields of physical security and information security, access control is the selective restriction of access to a place or other resource while access management describes the process. The act of accessing may mean consuming, entering, or using. Permission to access a resource is called authorisation.