My question has to do with virtual instruments - plugins. I've been away from the technology for a while and it looks like things have come a long way.

In the old days, you created MIDI files with a keyboard, then played them back thru the same keyboard utilizing the voices (patches) in that keyboard. You could change the patch in the software, but, if the 'tone generator' (keyboard) couldn't recognize that patch, it couldn't play it. But now, there's technology called 'virtual instruments'.

With a 'Soft synth' or 'virtual instrument' any instrument can now be digitally created on the computer. You create the MIDI track as usual, but then you can assign it any instrument in the software, and voila, it plays back as that instrument thru the audio (line) out of your MIDI interface. You don't have to play it back thru the MIDI keyboard, you simply run the line out to your amplifier.

What I want to make sure is.. is this really possible? I do understand this correctly? I really don't need a fancy tone generator or sound card or something else?