Power over Ethernet (PoE) technology enables regular network cables to work as power cords. In a PoE-enabled network, direct electrical current (DC) flows over the network cable together with normal Ethernet data traffic. Most PoE devices follow either IEEE standard 802.3af or 802.3at.
Power over Ethernet was designed for use with portable and wireless electronic equipment like Wi-Fi access points (APs), webcams, and VoIP phones. PoE allows network devices to be installed in ceilings or wall spaces where electric outlets are not within easy reach. A technology unrelated to PoE, Ethernet over power lines enables ordinary electric power lines to act as long-distance Ethernet network links.
The following infographic is a complete guide to Power Over Ethernet.