5.1, 7.1, 2.1 Soundcard/Speakers?

[vamp]

Hi. Can anyone please help explain to me what the difference is between these 3? I think 7.1 came after 5.1 which means its more advanced? Then I start hearing about new 2.1 speaker products recently, so I'm quite confused. I want to get a new speaker set and audigy card for my computer. I wonder which of these three would be best in terms of quality or for any reason you feel is most important. Thank you for any help.

[PCguy]

A 2.1 system only reproduces stereo. You won't be able to get the benefit of 5.1.

output 1 - front speakers

output 2- rear speakers

output 3- center and sub speakers

output 4-headset or back left and right speakers = 7.1

The two additional surround speakers give FPS gamers the advantage of precise positional audio that a 5.1 speaker system simply can't match.

[Restek]

I have a 4.1 setup and find it fine. I guess a 5.1 is good if you watch a lot of movies since DVDs are encoded in 5.1, personally I think 7.1 is OTT but then I've not had a chance to try it out either

[vamp]

Thanks guys.