A burglar alarm is a modern system of alarms particularly designed to detect any sort of violation, damage and illegal entry into buildings or specific places.

Burglar alarms are now commonly used in homes, markets and military areas for the protection against the increasing burglary and intrusion. Prisons are also protected with the help of these alarms to avoid escaping of convicts. It ranges from small to complicated systems according to the need of place.

Burglar alarms usually consist of one or more than one sensors. Different companies have now proposed different types of sensors like passive infrared detectors commonly found in homes and offices which detect heat produced by objects, Glass-break detectors which detect sound frequencies produced by breaking of a glass, Ultra sonic detectors which carry ultrasonic sound waves inaudible by human beings, Inertia sensors which particularly detects attack on the structure of the building, micro phonic sensors and many more for complete protection.