Digital audio can be transmitted through quite a few cable types, both as pure audio cable or combined with digital video cables.
Digital optical and X are among the most common digital cables for audio example transfer, e.g. between the TV box and flat screen or e.g. CD player, DA converter and amplifier.
The newer types of digital audio cables are used between e.g. multimedia players, computers and DA converters. Cable networks may be used for the actual network streaming of music, where USB cables typically connect computers or steaming players with DA converter and stereo amplifier.
HDMI cables are used for combined transmission of multi-channel digital audio and video signals. HDMI has gradually replaced a large number of analogue cables for both image and sound transmission and is the most common AV cable type.