Closed-circuit television (CCTV) is the use of video cameras to transmit a signal to a specific, limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point wireless links. CCTV is often used for surveillance in areas which need security, such as banks, casinos, and airports or military installations. Increasing use of CCTV in public places has caused debate over public security versus privacy. In industrial plants, CCTV equipment may be used to observe parts of a process that are remote from a control room, or where the environment is not comfortable for humans. CCTV systems may operate continuously or only as required to monitor a particular event.

Surveillance is the monitoring of behavior. Systems surveillance is the process of monitoring the behavior of people, objects or processes within systems for conformity to expected or desired norms in trusted systems for security or social control. Clinical surveillance refers to the monitoring of diseases or public health�related indicators (for example symptoms indicating an act of bioterrorism) by epidemiologists and public health professionals. Although the word surveillance in French literally means "watching over",[1] the term is often used for all forms of observation or monitoring, not just visual observation. Nevertheless, the all-seeing "eye in the sky" is still a general icon of surveillance. Surveillance in many modern cities and buildings often uses closed-circuit television cameras. Although surveillance can be a useful tool for law enforcement and security companies, many people have concerns about the loss of privacy.