what is power ethernet? and what is purpose of it?

Answer 1

Power over Ethernet or PoE technology describes a system to transmit electrical power, along with data, to remote devices over standard twisted-pair cable in an Ethernet network. This technology is useful for powering IP telephones, wireless LAN access points, webcams, Ethernet hubs, computers, and other appliances where it would be inconvenient or infeasible to supply power separately.

for more info, check these links;
http://www.hyperlinktech.com/web/what_is_poe.php
http://en.wikipedia.org/wiki/Power_over_Ethernet
http://www.poweroverethernet.com/

Answer 2

POE or Power over Ethernet uses unused wires in the Ethernet cable to deliver DC power (Usually 48 volts) to a Ethernet device. This is used commonly with IP based telephone systems and some WiFi products. If you have a remote Ethernet device that accepts POE, it can be more convenient to provide power this way than finding an A/C plug and installnig a power adapter in a remote location.

Answer 3

Power over ethernet is used to power ethernet devices that need to be placed were there are no convienent power outlets. If you want to place an access point down the line and it is POE capable you do not have to plug in the 110v adapter to power it as it will receive its power through its ethernet connection.