It uses two pairs of twisted copper wires in an Ethernet cable to deliver power to a powered device. It is not used very often because of its few applications and low power. One of the biggest advantages of copper twisted pair Ethernet cable (also called Category cable) is it's ability to perform two critical functions at the same time: When these functions are simultaneously performed, it is known as PoE or Power over Ethernet. PoE is considered safe, and hence its adoption is widespread. The technology conforms to IEEE standards, like 802.
