Describe a PoE injector.

What will be an ideal response?

PoE injector is a small, inexpensive device that can inject power into an Ethernet cable. These injectors can be endspan devices (such as a network switch enabled to provide power on each port) or a midspan device, which is connected inline to each end device and adds power to the line. Using PoE injectors, a standard, non-PoE-enabled Ethernet switch can be used to supply the data while the PoE injector provides the power.