How does DVD audio differ from CD audio?

DVD-Audio is a digital format for delivering high-fidelity audio content on a DVD. It is not intended to be a video delivery format and is not the same as video DVDs containing concert films or music videos. It offers many possible configurations of audio channels with far higher audio quality.
So DVD-Audio has much more functions than CD audio.

DVD audio recordings can provide far better sound quality than CDs. The chart below lists the sampling rate and accuracy for CD recordings and the maximum sampling rate and accuracy for DVD recordings. CDs can hold 74 minutes of music. DVD audio discs can hold 74 minutes of music at their highest quality level, 192kHz/24-bit audio. By lowering either the sampling rate or the accuracy, DVDs can be made to hold more music. A DVD audio disc can store up to two hours of 6-channel, better than CD quality, 96kHz/24-bit music. Lower the specifications further, and a DVD audio disc can hold almost seven hours of CD-quality audio.
In an audio CD or DVD, each bit represents a digital command telling the DAC what voltage level to output. While an ideal recording would follow the raw waveform exactly, digital recordings sample the sound at different frequencies, and therefore lose some of the data.