Questions about surround sound

[shoja]

So my friend is telling about not needing 5.1 speakers to get 5.1 surround sound and saying that 5.1 stands for channels, not speakers(?!). I know 5.1 is channels but don't you need 5 speakers and a sub-woofer to fully utilize all those channels? And then goes on to saying that some DSS(?) tech came out before 5.1 speakers even existed in 1940 which according to him is 5.1 channels technology. Then goes on to say that stereo headphones(like turtle beach) use dss to produce 5.1 sound like other true 5.1 surround sound headphones.

Lost by now? You should be because everything he said to me looks extremely inaccurate/made-up and has me extremely confused. I know a little about this whole surround sound thing. What is dss? I never heard of it and don't you need like 5 speakers in headphones to actually experience true surround(5.1)? And stereo headphones can just simulate it and not provide what a full 5.1 headphones(if there is any) can provide? Because if that guy is right then why are people buying 5.1 headphones or sound systems? Everyone can just go buy stereo and turn into 5.1 magically.

Please enlighten me fellow gurus because googling all this made me more confused

Thanks