Injector: Adds power to the network (Ethernet) cable. Used to power a PoE device (e.g. security camera) when your router or switch does not already provide power.
Repeater: Works as a repeater. Extends the range of the network signal and PoE power beyond the standard 100-meter limit, without requiring an additional power outlet in between.
Splitter: It does the opposite job of an injector. It takes the common PoE cable and "splits" the power from the data into two separate cables, allowing the powering of devices that are not PoE-enabled.
