My Z370-E motherboard has a black (labeled "rear") and green ("line out") audio output. See the image below (image credit Kit Guru).
I can use both with my headphones, but it isn't clear to me what the difference between them is. So what is the difference and when or for which devices should I use which port?
Best Answer
Your computer has a standard 5.1 surround soundcard on-board. This means that, in order to drive all 6 channels, you need 6/2=3 connectors.
Some onboard soundcards will send stereo output to the rear channel in case no connector is connected to the proper green connector. Other soundcards may simply up-mix the stereo sound to all channels to make the stereo sound come through all speakers.
The difference will be noticeable when you connect a 5.1 surround speakerset and you use/play a surround demo/movie. Then the rear channels will be mostly muted or have a lower volume in order to be able to get those channels played when audio comes from that direction.
Just for reference, the blue and purple connectors are input connectors, not output connectors. They are line-in and mic.