HDMI-CEC

Short for "HDMI - Consumer Electronics Control", TV's and their attached devices that include this feature can communicate back and forth, which allows features like a Blu-ray player's remote control changing the volume level on the TV, eliminating the need for grab the TV remote.  I'm fortunate that my Vizio TV calls this feature CEC, making it easy to recognize, while most others have some fancy trade name, which are listed towards the end of this very informative article.

https://www.howtogeek.com/207186/how-to-enable-hdmi-cec-on-your-tv-and-why-you-should/