The difference is: without SOCD you have to do the following to make a counterstrafe in CS2: let go of the movement key and then press "as fast as possible" the opposite movement key. So the moment the first movement key is disabled, the second movement key should be activated (of course only a tap, so you dont move in the other direction) - hence a perfect counter strafe and that means that you have perfect accuracy. With SOCD this is automated - you just need to tap the second movement key and you made a perfect counterstrafe with zero delay. Of course there is a debate how much SOCD is really worth it, optimum tech calls it 'cheating' (he wants generate klicks for his videos of course), dedicated cs streamers / youtubers don't think that SOCD makes much of a difference for skilled players (for example voo, austincs, 3kliksphillip, mrmaxim). However most of them seem happy, that SOCD is banned now.