Really hard to explain everything Spiderman in a few sentences, better to just wiki it if you have some time to read: http://en.wikipedia.org/wiki/Spider-Man
And yes, Spiderman and Superman aren't from the same universe or company. Spiderman is Marvel while Superman is DC Comics. And in essence, everyone could take a punch from Superman because he always holds back even against villains. If he doesn't, he'd likely knock the head off 99% of the villains he punches.