HDMI Vs. Optical Cable for Audio
Connecting various video and audio components can require the use of different cables. While HMI cables and audio cables can provide the same fundamental purpose, there are many variations in the transmissions of signal.
HDMI cables transfer uncompressed digital audio and video simultaneously through the same cable and connector.
Optical audio cables use pulses of light, created by LED's, to transfer audio signals.
HDMI Vs. Optical
Both HDMI and Optical cables provide high quality audio, but the audio provided by HDMI is superior because not only is the digital signal uncompressed but also is transmitted simultaneously with the video.