I have run a 15m (50ft) Cat6 cable from my modem on the main floor to the basement entertainment unit. At that unit I have a PS4, TV and Fire Stick. I want to connect both the TV and the PS4 to ethernet for now (Fire stick later if I buy the adapter). Do I just need a splitter at the entertainment unit end of this cable and will be good to go?
Later, if I get an unmanaged multiple-port switch for my main floor devices, can/should I connect this cable to the switch on the main floor, or should I leave it connected straight to the modem?
You need a switch at your entertainment center. They are relatively cheap.
Not sure what a splitter is but you don’t need it.