I don't know if this helps, I've just searched the internet:
http://www.musicdsp.org/phpWiki/index.php/WhatIsVST
the point is that VST are efects you can use to process your audio recordings...
check out this, too:
http://en.wikipedia.org/wiki/Virtual_Studio_Technology
I'm not sure what that guy wanted to tell you, but I suppose he was talking about getting software that supports VST plug-ins, because, I think, Audacity doesn't support them fully, because of some legal issues with Steinberg...
Please somebody correct me if I'm not right...