Some (many?) HDMI cables can also carry Ethernet over HDMI. The main use seems to be to provide internet connection to a smart TV from a cable modem box. Currently I have an ethernet-USB adaptor ...

Is there is no sound when your computer is connected to TV with HDMI cable, check your default audio device & then use these effective fixes.

Older HDMI cables still work: use them for retro consoles, secondary TVs/monitors, and laptop connections. Don't toss ...

But what if you have a computer with only one HDMI port and you're already using it or want to have two monitors instead of just one? Good news, you're not out of options.