The usual power supply for most of the surveillance cameras is a simple adapter (transformer) providing 24 Volts of alternating current or 12 Volts direct current. It may be included in the package or else it may need separate purchase.
For multiple camera setups, depending on outlet locations, it may be more economic to procure a central adequate power supply with individual wires to the different cameras. In any case the power supply has to be plugged in a normal household outlet with a power cord of about 2 m (6 ft).
If the camera is placed far from available current taps but no more than 100 m (350 ft.), a pair of low voltage (24 V) power wires (speaker wire, 18 or 20 gage) is all that is needed.
CCTV Accessories. Cable, Power Supply, Connectors.
Coaxial cables (for video transmission) are available with power wires embedded in the insulation. Another combination system exists that lets the video signal and the power supply run on the same coaxial cable, especially convenient if the camera is to be driven from a central location. This solution may have some merits in certain situations, but it is definitely discouraged for simple do-it-yourself applications.