Difference between stereo A/V CBR and stereo CBR

[Prober]

I use Xilisoft WMA MP3 Converter to convert file to WMA format.

There is a lot of settings to choose and to set for the audio file.

I just don't understand what is the difference between stereo A/V CBR and stereo CBR in audio?

What is Stereo Low Delay CBR and VBR Quality?

And what is sample rate?

[jcarle]

Google.

Wikipedia.

Please to be learning.

Sampling Rate.

CBR.

VBR.