eARC stands for Enhanced Audio Return Channel. It's an updated version of the standard ARC feature that allows higher-quality audio and more advanced features to be sent over the HDMI cable.
Some of the critical features of eARC include
To take advantage of eARC, both the source device and the TV or projector (or other display devices) must support eARC, and the HDMI cable connecting them must be capable of supporting eARC.
More modern projectors with eARC functionality can automatically detect an eARC or ARC connection, configuring it for the user. If the projector does not support an automatic connection, it’s not a problem. The user must activate the eARC feature on both devices and set the TV or projector's audio output to "eARC.".