Closed-circuit television (CCTV), also known as video surveillance, is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point-to-point (P2P), point-to-multipoint (P2MP), or mesh wired or wireless links. Even though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that require additional security or ongoing monitoring (Videotelephony is seldom called "CCTV").
Surveillance of the public using CCTV is common in many areas around the world. Video surveillance has generated significant debate about balancing its use with individuals' right to privacy even when in public.
In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room, especially if the environments observed are dangerous or inaccessible to humans. CCTV systems may operate continuously or only as required to monitor a particular event. A more advanced form of CCTV, using digital video recorders (DVRs), provides recording for possibly many years, with a variety of quality and performance options and extra features (such as motion detection and email alerts). More recently, decentralized IP cameras, perhaps equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation.
By one estimate, there will be approximately 1 billion surveillance cameras in use worldwide by 2021.[needs update] About 65% of these cameras are installed in Asia. The growth of CCTV has been slowing in recent years.[unreliable source?] The deployment of this technology has facilitated significant growth in state surveillance, a substantial rise in the methods of advanced social monitoring and control, and a host of crime prevention measures throughout the world.
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.
Greater Manchester is a metropolitan county and combined authority area in North West England, with a population of 2.8 million; comprising ten metropolitan boroughs: Bolton, Bury, Oldham, Rochdale, Stockport, Tameside, Trafford, Wigan, and the cities of Manchester and Salford. Greater Manchester was created on 1 April 1974, as a result of the Local Government Act 1972, and designated a functional city region on 1 April 2011. Greater Manchester is formed of parts of the historic counties of Lancashire, Cheshire and the West Riding of Yorkshire.
Greater Manchester spans 493 square miles (1,277 km2), which roughly covers the territory of the Greater Manchester Built-up Area, the second most populous urban area in the UK. Though geographically landlocked, it is connected to the sea by the Manchester Ship Canal which is still open to shipping in Salford and Trafford. Greater Manchester borders the ceremonial counties of Cheshire (to the south-west and south), Derbyshire (to the south-east), West Yorkshire (to the north-east), Lancashire (to the north) and Merseyside (to the west). There is a mix of high-density urban areas, suburbs, semi-rural and rural locations in Greater Manchester, but land use is mostly urban—the product of concentric urbanisation and industrialisation which occurred mostly during the 19th century when the region flourished as the global centre of the cotton industry. It has a focused central business district, formed by Manchester city centre and the adjoining parts of Salford and Trafford, but Greater Manchester is also a polycentric county with ten metropolitan districts, each of which has at least one major town centre and outlying suburbs.
Greater Manchester is governed by the Greater Manchester Combined Authority (GMCA), which consists of political leaders from each of the ten metropolitan borough councils, plus a directly elected mayor, with responsibility for economic development, regeneration and transport. Andy Burnham is the inaugural Mayor of Greater Manchester, elected in 2017. For the 12 years following 1974, the county had a two-tier system of local government; district councils shared power with the Greater Manchester County Council. The county council was abolished in 1986 and so its districts (the metropolitan boroughs) effectively became unitary authority areas. However, the metropolitan county continued to exist in law and as a geographic frame of reference, and as a ceremonial county, with a Lord Lieutenant and a High Sheriff. Several county-wide services were co-ordinated through the Association of Greater Manchester Authorities between 1985 and 2011.
Before the creation of the metropolitan county, the name SELNEC was used for the area, from the initials of "South East Lancashire North East Cheshire". Greater Manchester is an amalgamation of 70 former local government districts from the former administrative counties of Lancashire, Cheshire, the West Riding of Yorkshire and eight independent county boroughs. Since deindustrialisation in the mid-20th century, Greater Manchester has emerged as a major centre for services, media and digital industries, and is renowned for guitar and dance music and its association football teams.