The term refers to a collection of digital processes and formats that allow the encoding and playback of music using higher sampling rates than the standards used in CDs.
The graphs above start with the original analog sound waves and illustrate the low sample rate of CDs compared to the greater frequency used to record High-Resolution Audio. There is no single standard for High-Resolution Audio, but the most commonly used specifications are 24-bit/96 kHz (3.2x more data transmitted than CD) and 24-bit/192 kHz (6.5x more data transmitted than CD).