PoE is a technology for wired Ethernet. Thus, the electrical power needed to operate each device can be carried by data cables rather than by power cords. It minimises the number of wires that must be strung in order to install the network. PoE also potentially reduces the cost of installing end devices, such as IP phones and wireless LAN access points.
Because the network switches also can deliver power through the standard Ethernet infrastructure, you no longer need to connect each IP phone or wireless LAN access point to a separate electrical circuit and install additional AC power outlets. Also, PoE can provide customers with uninterruptible power for critical applications such as IP (Internet protocol) phones, security cameras, entry loggers, and other powered data terminals.