Basic Facts about Power Over Ethernet (PoE)
Power Over Ethernet (PoE) is a networking technology that enables Ethernet cables to carry electrical power in addition to data packets. In PoE enabled networks, direct current (DC current) travels over a single Cat6 or Cat5e Ethernet cable. PoE technology-enabled devices are designed to comply with at least one or multiple IEEE standards. Let us share which PoE standards are available to date.
Thus, this technology can bring significant cost reductions and simplicity in any small to medium office network. However, it is essential to understand that you cannot stretch a PoE link beyond the maximum link distance of 100 meters. On the other hand, in conventional ethernet networks, dedicated power cables and power supplies are used for the associated loads.
Conventional (Non PoE) Ethernet VS. Power Over Ethernet (PoE)
The following two images are showing how PoE is different from conventional Ethernet. As you can see, in conventional Ethernet, DC power is being provided from an external source. Whereas, in PoE, the connected devices are receiving the necessary power + data from a PoE enabled switch.