Closed-circuit television (CCTV) is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted...
Wikipedia pretty much sums it up in the above sentence - video cameras transmit a signal to a specific place - that specific place could be a recording unit, a TV/monitor or even a PC / Smartphone etc.
However - the signal is not openly transmitted - is not entirely accurate. When CCTV was first invented it was definitely a "closed circuit" but modern CCTV systems are nearly all networkable. The simple fact that you can network the system and stream the images over the internet, in theory make it an open circuit - of course the signal is encrypted and password protected, but it is certainly debatable whether it can be classed as a closed circuit. Obviously if you have an SD CCTV or HD over Coax system and choose not to physically connect it to the network, then it would still be a completely closed circuit.
As already mentioned above there are several CCTV formats to choose from; SD CCTV (also known as Analogue CCTV), HD over Coax CCTV and IP CCTV.
What format?
Choosing the format is the most important decision you will make, the formats are not inter-compatible so take plenty of time when deciding. To read information about each format click on below links:
