DVB S stands for Digital Video Broadcasting Satellite.
DVB S2 stands for Digital Video Broadcasting Satellite Second Edition.
DVB S2 uses BCH algorithm instead of Reed Solomon coding which is better error correction coding.Also DVB S2 uses fewer data for correction in comparison with DVB S.
DVB S2 have the backward compatibility means DVB S2 receiver can also receive DVB S signal.
DVB S2 increase the channel capacity by 30% per transponder means S2 can carry 30% more services than DVB S.
Well DVBS is basically SD (NOT HD) and DVBS2 is HD. Now why is that so Important, well if you have a flatter and bigger tv having DVBS2 is much better cuz it got upto 5 times better picture and much better sound. And so the picture doesn’t look like crap on a bigger tv, cuz if you use SD on a HD tv it will stretch out the picture and it will look bad and not clear.
So speaking technically DVBS sends in MPEG2 like what you find in DVD`s, and DVBS2 sends in MPEG4 witch is a better compression algorithm. Forexample bluray disc got MPEG4. Now don’t forget just because you have MPEG4 doesn’t mean its HD. To have HD it must be from 720 to 1080 lines of resolution, and with SD its 480 to 576 lines.