Fire alarm control panel – the system hub monitors inputs and system integrity, controls outputs and relays information. Primary power supply – primary power for your fire alarm system is usually supplied in the form of 124V or 240V AC from the power company. Secondary (backup) power supply – backup power supplies usually consist of lead-acid batteries used to power the system in case the primary power source fails. Initiating devices – these are your activation stations, and can be manual (pull stations) or automatic (smoke detectors). Notification appliances – notification appliances are things like flashing lights, strobe lights, horns, speakers, etc. that actually let people know of the danger in your building. Building safety interfaces – these are things like exit lighting, ventilation systems, etc. that make it easier for people to get out of the building once a fire has started.