A whole new set of applications become feasible with PoE switches due to reduced installation costs through ease of setup and the ability to remotely power end devices. Some common Ethernet devices that a Power over Ethernet switch may be able to power are: Access Points, IP Cameras, Serial Servers, and Ethernet I/O. The PoE ports on these switches follow Alternative A standards and are limited to 15.4 or 25 Watts of power output per port.
PoE stands for Power over Ethernet, which is just what it says. Power is transmitted over the Ethernet cable along with the data lines. Each PoE switch has a set of ports that is classified as power source equipment (PSE). These ports can be used to power IEEE 802.3af compliant powered devices (PD), eliminating the need for a separate power line to be run to each end device.
