[LAU] PulseAudio - Internal Audio

[Vangelis Katsikaros]

Hello

I am a total noob when it comes to sound in linux. I have Ubuntu and I 
was trying to record what I was hearing. I did it but I have a question.

I installed PulseAudio Volume Control (pavucontrol) and noticed the 
"Configuration" tab, where it has an "Internal Audio" profile with 
options like:
* Analog Stereo Duplex
* Analog Stereo Output
* Digital Stereo Duplex (iec 958) + Analog Stereo Intput
* Digital Stero Duplex (iec 958)
* Off

I tried to find more information about these options, but there is no 
"help" for this GUI. SO I was wondering if anyone could give any hints 
(links, documentation etc) on what these settings are.

Vag