12 volts - power for most IP cameras. It can be provided with either a conventional power supply or with an Ethernet cable with PoE standard. This allows you to use the camera where the supply of other power is completely absent.
For IP cameras with PoE, there is a limit in the range of 100 meters from the power source. When you connect all the cameras to the PoE switch, it becomes possible to provide electricity to the entire CCTV system - connected cameras.