A security alarm is a system designed to detect intrusions, such as unauthorized entry, into a building or other areas, such as a home or school. Security alarms protect against burglary (theft) or property damage, as well as against intruders. Examples include personal systems, neighborhood security alerts, car alarms, and prison alarms.
Some alarm systems serve a single purpose of burglary protection; combination systems provide fire and intrusion protection. Intrusion-alarm systems are combined with closed-circuit television surveillance (CCTV) systems to record intruders' activities and interface to access control systems for electrically locked doors. There are many types of security systems. Homeowners typically have small, self-contained noisemakers. These devices can also be complicated, multirole systems with computer monitoring and control. It may even include a two-way voice which allows communication between the panel and monitoring station.
London Colney (/ˈkoʊni/) is a village and civil parish in Hertfordshire, England. It is located to the north of London, close to Junction 22 of the M25 motorway.
It is around 2.5 miles (4.0 km) south-east of St Albans city centre (and within said city's contiguous built-up area) and part of the City and District of St Albans. At the time of the 2001 census the population of London Colney ward was 7,742, increasing to 9,507 at the 2011 Census. It is considered a satellite or dormitory village of St Albans, where some villagers travel to work and shop.