Some 4K Blu-ray players have an extra HDMI port for this interesting reason

HDMI ports are everywhere these days, and while they all look the same, many of them do totally different things. For the most part, the ports that are on your TV are just meant to display video and give you audio, but even those have differences. The big one to be aware of there is the eARC port that is meant to handle your audio equipment. This port gives you the best bandwidth that you can have, and it’s essential you plug your sound system into it.