Closed-circuit television in the context of "Videotelephony"

A webcam is a video camera which is designed to record or stream to a computer or computer network. They are primarily used in video telephony, live streaming and social media, and security. Webcams can be built-in computer hardware, like a laptop, or peripheral devices, and are commonly connected to a device using USB or wireless protocol.

Webcams have been used on the Internet as early as 1993, and the first widespread commercial one became available in 1994. Early webcam usage on the Internet was primarily limited to stationary shots streamed to web sites. In the late 1990s and early 2000s, instant messaging clients added support for webcams, increasing their popularity in video conferencing. Computer manufacturers later started integrating webcams into laptop hardware. In 2020, the COVID-19 pandemic caused a shortage of webcams due to the increased number of people working from home and children attending school remotely.

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.

A security guard (also known as a security inspector, security officer, factory guard, or protective agent) is a person employed by an organisation or individual to protect their employer's assets (property, people, equipment, money, etc.) from a variety of hazards (such as crime, waste, damages, unsafe worker behavior, etc.) by enforcing preventative measures. Security guards do this by maintaining a high-visibility presence to deter illegal and inappropriate actions, looking (either directly through patrols, or indirectly by monitoring alarm systems or video surveillance cameras) for signs of crime or other hazards (such as a fire), taking action to minimize damage (such as warning and escorting trespassers off property), and reporting any incidents to their clients and emergency services (such as the police or emergency medical services), as appropriate.

Security officers are generally uniformed to represent their lawful authority to protect private property. Security guards are generally governed by legal regulations, which set out the requirements for eligibility (such as a criminal record check) and the permitted authorities of a security guard in a given jurisdiction. The authorities permitted to security guards vary by country and subnational jurisdiction. Security officers are hired by a range of organizations, including businesses, government departments and agencies and not-for-profit organizations (e.g., churches and charitable organizations).

A closed-circuit television camera is a type of surveillance camera that transmits video signals to a specific set of or video recording devices, rather than broadcasting the video over public airwaves. The term "closed-circuit television" indicates that the video feed is only accessible to a limited number of people or devices with authorized access. Cameras can be either analog or digital. Walter Bruch was the inventor of the CCTV camera.

A prison escape (also referred to as a bust out, breakout, jailbreak, jail escape or prison break) is the act of an inmate leaving prison through unofficial or illegal ways. Normally, when this occurs, an effort is made on the part of authorities to recapture them and return them to their original detainers. Escaping from prison is also a criminal offense in some countries, such as the United States and Canada, and usually results in time being added to the inmate's sentence, as well as the inmate being placed under increased security that is usually a maximum security prison or supermax prison. In Germany and a number of other countries, it is considered human nature to want to escape from a prison and it is considered as a violation of the right of freedom, so escape is not penalized in itself (in the absence of other factors such as threats of violence, actual violence, or property damage).

Many prisons use security features such as CCTV, perimeter sensors, barred windows, high walls, barbed wire, razor wire, and electric fencing to prevent escapes. Even natural geographic features can play significant roles in preventing escapes; historically, mountains and islands were chosen as ideal settings for prison construction, given their significance in creating territorial isolation from outside worlds.