Surveillance is the monitoring of the behaviour, activities, or other changing information, usually of people and often in a surreptitious manner. It most usually refers to observation of individuals or groups by any organizations.The word surveillance comes from the French word for "watching over".
The word surveillance may be applied to observation from a distance by means of electronic equipment (such as CCTV/IP cameras), or interception of electronically transmitted information (such as Internet traffic or phone calls).
Surveillance is very useful for any organizations to maintain social control, recognize and monitor threats, and prevent/investigate criminal activity. With the advent of programs such as the Total Information Awareness program and ADVISE, technologies such as high speed surveillance computers and biometrics software,
Surveillance cameras are video cameras used for the purpose of observing an area. They are often connected to a recording device, IP network, and/or watched by a security guard/law enforcement officer. Cameras and recording equipment used to be relatively expensive and required human personnel to monitor camera footage. Now with cheaper production techniques, it is simple and inexpensive enough to be used in home security systems, and for everyday surveillance. Analysis of footage is made easier by automated software that organizes digital video footage into a searchable database, and by automated video analysis software. The amount of footage is also drastically reduced by motion sensors which only record when motion is detected.