In general, closed circuit television systems are basically composed of cameras, transmission medium, power supply, video and recording management system, display medium and, of course, who operates or consults it, that is, the factor human.

It is important to remember that there are two types of CCTV systems: analog and IP-based. The former use continuous electrical type signals that are transported in a physical or wireless medium between the camera and the recording system, while network or IP video systems use digital type signals also transmitted by physical or wireless means. wireless, but under the TCP / IP protocol in Ethernet-type networks.

Video and recording signal management systems are commonly referred to as DVR (Digital Video Recorder) for analog video systems. For small projects or applications, the same DVR with software that most manufacturers provide along with the equipment fulfills the functions of video management and recording.

The most used physical medium for transmission of the analog video signal between the camera and the DVR is the coaxial cable; However, the use of twisted pair cable (UTP), plus the implementation of video-balun’s is increasingly common due to the lower cost that this type of cable represents compared to coaxial.