[!@#$%!]

cardinal rob, in this case soundcard=firewire interface, it's the same thing

your computer has a soundcard (what you hear through the speakers), but rather than jack your mixer into it, with all the additional componets & electronics & distortion, you feed the audio signal through its own little shielded box & firewire cable, with the added benefit that all the channels from your mix are preserved for whatever multitrack software you choose to work with.