The SuperAudioCD is an optical audio storage standard that was created to compete against DVD-Audio in an effort to replace the CD.
Developed by Sony and Philips, SACD was created for audiphiles that wanted a better experience and quality from their CDs than stereo sound.
SuperAudioCD promised a multi-channel listening experience, unlike the simple stereo that is available on CDs.
An SACD disc sounds better than a CD for a few reasons. An SACD is capable of capturing sound up to 100kHz using sampling up to 2800kHz (2.8 MHz). A CD can only handle up to 44.1kHz. An SACD has the same capacity as a DVD-5, about 4.7GB, 8x the capacity of a regular CD. Using Direct Stream Digital, the music can be delivered either as 2.0 stereo or via 5.1 channels with no loss in quality from the transfer.
DsD also removed the need for Delta-Sigma modulation and Decimation and Interpolation filters which means the music you hear from an SACD is as natural as possible.