CCTV cameras can produce images or recordings for surveillance purposes, and can be either video cameras, or digital stills cameras. From a single camera and monitor to complex video surveillance systems with hundreds of cameras, multiple operators, and digital recorders, closed circuit television (CCTV) systems can provide security for a wide range of businesses.

A good video surveillance system can make your business safer, more efficient, and less prone to theft and accidents. Specifically, video surveillance can provide many benefits:

• Reduce shrinkage by catching shoplifters
• Monitor cash registers
• Record evidence to prevent bogus accident claims
• Identify visitors and employees
• Monitor hazardous work areas
• Increase security in and around business premises and parking lots
• Meet insurance requirements

A basic CCTV system consists of the following:

• Lens - The function of the lens is to collect the light from the scene and form an image of the scene on the sensitive camera tube or chip.
• Camera - The camera containing the sensitive image tube or chip, converts the visible scene formed by the lens onto the tube or chip, into an electrical signal which is then made suitable for transmission via coaxial cable or other transmission means to the monitor.
• Coaxial Cable - The function of the cable (or other signal transmission method) is to transmit the electrical camera scene signal to the monitor.
• Monitor - The monitor displays the camera picture by converting the electrical signal back into a visible picture.
• Digital Video Recorder (DVR) - These machines record the monitor picture from the camera onto hard drives instead of tape.

If the requirement is for more than one camera to be used, then the inclusion of a video switcher or multiplexor is required. In the case of a switcher this allows a single monitor to switch through all the cameras on the system. A multiplexor enables simultaneous transmitting and recording of all cameras.