Power over Ethernet technology, or PoE, describes a system (digital signage, or otherwise) to support both the electrical power and the data over a standard network cable. This technology allows users to remotely control and power a device via one single cable. It is flexible, reliable, safe and cost-effective. In the world of AC to DC, DC to DC, polarity, or maximum input voltages. We can negate all that and use one less cord and on top of that reduce the cost of installation. Power over Ethernet (PoE) provides power by plugging one end of an Ethernet cable to your PoE enabled device and the other end connects to a PoE switch or PoE injector. This enables the elimination of a power cable and both power and data are delivered over a twisted pair via Ethernet cable. Common applications are VoIP phones, IP cameras (including pan-tilt-zoom), wireless access points, IPTV decoders, network routers, POS, lighting controllers, industrial devices, wall clocks, physical security devices and controllers, etc.