Video surveillance systems are used both at home and in commercial establishments to monitor the movement of people. Also known as closed circuit TV (CCTV), they are used to monitor pathways and insecure areas around homes and to prevent break-ins and intrusions.

A video surveillance system is made up of the following components:

Monitors. These are used to display video information processed by the cameras placed strategically in and around the house. Monitors have better video resolution than standard television receivers. The resolution of a black-and-white CCTV monitor, ranges from 700-1000 lines, whereas color monitors have a resolution of 350-400 lines.

Cameras. These are placed at strategic locations to monitor the movement of suspicious or unknown persons. They send this information to the monitors.

Coaxial cabling. This is used to transport video information from the cameras to the monitors.

Switchers. These are used to hook two or more cameras to a monitor. Advanced switchers allow you to hook up alarm inputs, so that the corresponding camera is targeted and locked when the alarm is activated.

The camera. This is the most important component in any video surveillance system. Great care should be taken when buying it. Some of the points to keep in mind when buying a camera are:

* How many cameras are needed in order to effectively monitor the exterior and interior of a home?

* Is there a need for both visual and audio inputs?

* Should the cameras take black-and-white or color images?

* Should the cameras be wired or wireless?

The placement and installation of cameras is also important. The following points should be kept in mind before installing a camera:

* The farther back the camera is placed, the larger the area it views will be. However, the clarity will be proportionately reduced.

* There should be no blind spots caused by boundaries, trees, poles etc.

* The height at which the camera is placed should be such that it is not easily accessible from the ground.

A user has several options when selecting a home video surveillance system. He or she can have the security cameras connected to a PC, a TV, and/or a VCR. The camera can be wireless or wired. The user also has the option to use spy (hidden) cameras.

The user can install the video surveillance system him- or herself, or can hire a video surveillance and monitoring service to carry out the task.