Power-over-Ethernet (PoE) is a feature that allows network devices to be powered directly from a switch instead of from an outlet or other power supply.

Prior to 2003, switches could only transmit data through their ports. After PoE was standardized by IEEE, manufacturers were able to produce switches capable of transmitting power and data through designated ports.

The key benefit of PoE is that it saves on the cost of extra cabling, trenching, and installation.