The tvOS 14.6 update is free and can be downloaded via the Settings app on the Apple TV by going to “System” -> “Software Update.” If you have automatic software updates turned on your Apple TV will be upgraded to tvOS 14.6 automatically.
tvOS 14.6 lays the groundwork for the new Apple Music Spatial Audio with Dolby Atmos and Lossless Audio features.
Dolby Atmos is a form of Spatial Audio, which offers an immersive three-dimensional sound experience for the listener. Meanwhile, Apple Music Lossless offers higher quality audio.
In June, Apple will begin offering Apple Music subscribers a “Standard” Apple Music Lossless option with audio up to 48kHz, and “Hi-Res Lossless” with audio between 48kHz and 192kHz.