High-Resolution Audio systems offer the promise of an extended high-frequency range. High-Resolution digital systems now operate at 2 to 4 times the sample rate of the standard CD. This means that these systems have the capability of extending the playback frequency range well above the 22 kHz limit of the standard CD. Does this added high-frequency range improve our listening experience? How high is high enough? Do we really need anything over 20 kHz?
There is a raging debate over the definition of "High-Resolution Audio". The focus of this debate has been misdirected by a lot of marketing hype. High-Resolution Audio will only truly arrive when the sum total of all defects in the audio chain become inaudible. We are not there yet, but we are getting close. The final chapter will not be higher sample rates and more bits. The final chapter will be achieving the necessary improvements to critical components in the signal chain.
If your playback system can't resolve anything better than CD quality, then "High-Resolution Audio" will remain an illusion.