Power over ethernet sends power and data down one cable. It is worth it where there is no outlet near the display, where you want one cable instead of two behind a screen, and where IT wants to power cycle a player remotely from the switch.
There are two ways to add it to a Raspberry Pi based player.
A PoE HAT
A Hardware Attached on Top board sits inside the case, which is the tidier result.
The official Raspberry Pi Foundation PoE HAT needs a Raspberry Pi 3 Model B+ or later.
Three things to check before you buy one. Some HATs include a fan, and fans fail, which can shorten the life of an otherwise solid-state device. If you use a heatsink, and we use one in all our players, the HAT may not physically fit alongside it. And you will likely need a taller case.
A PoE splitter
An external splitter takes the PoE cable and gives you separate data and power leads. It is less tidy than a HAT and it avoids the fit and cooling questions entirely.
Either way
The switch has to supply PoE, and the power budget has to cover the board plus anything attached to it.
This applies to the standard, Raspberry Pi based player. A Player Max is not powered over ethernet: it uses a DC supply.