A fire alarm system is number of devices working together to detect and alert people through visual and audio appliances when smoke/fire is present. These alarms may be activated from smoke detectors, heat detectors, water flow systems, which are automatic or from a manual fire alarm pull station.

• Manually actuated devices; also known as fire alarm boxes, manual pull stations, or simply pull stations, Break glass stations, call points or Buttons. Devices for manual fire alarm activation, are installed to be readily located (near the exits), identified, and operated.
• Automatically actuated devices can take many forms intended to respond to any number of detectable physical changes associated with fire: convected thermal energy; heat detector, products of combustion; smoke detector, radiant energy; flame detector, combustion gasses; fire gas detector, and release of extinguishing agents; water-flow detector. The newest innovations can use cameras and computer algorithms to analyze the visible effects of fire and movement in applications inappropriate for or hostile to other detection methods.