An alarm system is a system designed to detect intrusion also known as unauthorized entry, into a building or other area. Security alarms are used in residential, commercial, industrial, and military properties for protection against burglary or property damage, as well as personal protection against intruders.
Open spaces inside of homes can be secured with motion sensors. When a door or window is closed, the two parts of the sensor are joined together, creating a security circuit. When the security system is armed at the control panel, these sensors communicate with it by reporting that the point of entry is secure.
Some alarm systems serve a single purpose of protection from burglaries, where combination systems provide both fire and intrusion protection. Intrusion alarm systems may also be combined with CCTV systems to automatically record the activities of intruders and may interface to access control systems for electrically locked doors. Systems range from small, self-contained noisemakers, too complicated, multiarea systems with computer monitoring and control. It may even include two-way voice which allows communication between the panel and Monitoring station.