POE stands for (Power Over Ethernet). In accordance with the abbreviation of the POE, in everyday language it can and can be interpreted as “distribution of electricity using an ethernet cable or network cable”. This electricity is channeled through 2 pairs of UTP cables, it can be 1,2,3,6 or 4,5,7,8.
POE which is generally used refers to the IEEE 802.3af standard where the maximum power per port is 15.4W, but due to the large number of new devices that require a higher power supply (eg for 802.11n 3×3 or 4×4) APs, a new standard is created, namely IEEE 802.3at. where the maximum power per port is 34.2.
POE is used to provide a solution to the difficulty of finding a power source when installing devices such as Access Points, IP Cameras and IP Phones. Imagine if there is no POE and we are required to install an Access Point or IP Camera in a large room, the costs will be high because each device requires 2 pulls, namely the UTP cable for data and the power cable (along with the power outlet). With PoE, we only need to pull one cable, namely the UTP cable.
So a little explanation about the definition of POE and its functions, hopefully it will be useful.