Revo Elite And BNC Ports on a DVR

What are These Extra ports on the back of my DVR?
On our bigger DVRs, such as the 16 channel, or the high-end pro units such as Revo Elite, there are BNC ports that are circular,
What are BNC Ports?
Short for Bayonet Neill Concelman connector, (sometimes erroneously called a British Naval Connector or Bayonet Nut Connector,a type of connector used with coaxial cables such as the RG-58 A/U.  All Revo Elite, PTZ Cameras, and Pro cameras will need BNC ports to connect to, or Converter Kits
What comes with Revo Elite / BNC Cameras?
Right now just the camera is included,you have to make sure to have BNC cable, and a source of power for the camera, since power is not carried on a normal BNC Cable, but it is on a Siamese BNC Cable