CCTV or Closed Circuit Television refers to a visible or covert video system intended for only a limited number of viewers. In Closed Circuit TV (CCTV), the picture is viewed or recorded, but not broadcast. It was initially developed as a means of security for banks and casinos; however, today it has been developed to the point where it is simple and inexpensive enough to be used with Home Security Systems, and for everyday surveillance.
A security camera can come in many different styles including dome, bullet, infrared and c-mount. The security camera that will work best for your application will depend on several factors such as whether you will use the security cameras inside or out, during the day, nighttime, or both.