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. PoE saves on the cost of extra cabling, digging, and installation.

PoE was first standardized by IEEE in 2003. Six years later in 2009, PoE+ was implemented. A full nine years later in 2018, PoE++ burst onto the scene. Many of the improvements with each iteration involved port power and voltage range, supported cables, and twisted pairs used.

The chart below details the differences among the PoE iterations. It’s important to remember that the power grand total for a port doesn’t mean that the maximum power for every port can be used simultaneously. Users hardly ever need to use full power at all times. Each switch has a maximum power load that the power being used by the ports cannot exceed.