CAT5E is a standard computer network cable with 4 pairs of wires inside. Your recorder will have BNC coaxial connections on the rear (silver round twist fit connections). Your cameras signal is usually supplied by a coaxial cable (resembles an aerial cable/sky TV cable) and a separate power cable. However it’s fairly standard practice to use a CAT5E cable. The benefit is that the cables are smaller/more manageable. Also the video and power can be carried in the same cable (using 2 of the 4 pairs - 1 for power, 1 for video). It will be clear if this is the case by looking behind your recorder as you’ll see the connections to the recorder leading to small devices called ‘baluns’ into which the CAT5E cable is connected (these devices convert the signal from balanced to un balanced). Sometimes there can be interference when multiple cameras are transmitted in one cable.
