A:Answer You need an HDMI cable for the output signal to get to your TV or HDMI source switch. If you had a good cable from before going to this player, it will work fine for this one; otherwise it is a good idea to get a better cable than the cheapest ones for this bandwidth of signal.
You don't need an Ethernet cable as it has Wi-Fi. You only need to connect to Wi-Fi if you plan on using the apps on the BD player. The apps on this unit are good, but could be redundant if you have another device that has apps (the TV itself or you have another app device like Roku, AppleTV, etc.)
