Power over Ethernet (PoE) describes any of several standard systems that pass electric power along with data on twisted pair Ethernet cabling. This allows a single cable to provide both data connection and electric power to devices such as wireless access points, IP cameras, and VoIP phones. Power over Ethernet allows the electrical current necessary for the operation of each device to be carried by the data cables rather than by power cords.
PoE+ is the latest IEEE standard that makes it possible for more devices to be supported by PoE than ever before. POE was originally developed to push power to phones and wireless access points.
The big difference between PoE and PoE+ is the amount of power delivered over each standard.
802.3af (PoE) can deliver 15.4 watts over Cat5 cables.
802.3at (PoE+) can deliver up to 30 watts over Cat 5 cables with 25.5 watts available to devices.
When vetting a PoE solution, be cognizant of what types of devices are on your network, what kind of power draw these devices create, and what they actually require.