All DVD players include at least one digital audio output for sending the Dolby Digital or DTS bitstream to a compatible decoder. Digital data transfer offers extremely wide bandwidth, immunity to radio frequency (RF) interference, and an easy one-cable connection. The two most common types of digital output are coaxial and optical. Both types require a special cable to connect to the digital input of your Dolby Digital/DTS-equipped in-dash receiver or surround processor.
A pure digital audio signal output that allows for a digital connection. The output comes in either a coaxial cable (RCA type)or a TOSLink optical cable. Digital outputs provide less noise and interference than any other type of connection.
most DVD players have digital audio outputs in order to send a Dolby Digital soundtrack to a Dolby Digital decoder or Dolby Digital TV. These digital outputs are normally either co-axial or optical, though many DVD players are equipped with both.