A security alarm is a mechanism that senses unwanted intrusion into a structure or other area, such as a home or school. Burglary (theft) and property damage are protected by security detectors in residential, commercial, agricultural, and military buildings, as well as personal defenses from intruders.

The use of a Security Alarm System For Home In Gurgaon for home detectors in suburban neighbourhoods has been linked to a reduction in crime. Car alarms also assist in the security of cars and their contents. Protection devices are also used in prisons to keep track of prisoners.

Such warning devices are only designed to defend against burglary; others are designed to protect against both fire and intrusion. Intrusion warning systems can be used in conjunction with closed-circuit television monitoring (CCTV) systems to remotely monitor intruder activity, as well as access control systems for electrically locked doors. Small, self-contained noisemakers to complex, multi-rally systems with computer monitoring and control are all available. It might also have a two-way voice for contact between the panel and the monitoring station.