The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
In no event shall Author be liable for any damages wha2tsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
The principal difference is the wattage supported per port, 15, 30 and 60W.
Another difference is UPoE uses 4 pairs of twisted cables, the other two uses 2 pairs.
Coming to a Cat 9400: Jumbo PoE (100w) (aka Mother-of-all-PoE)