I apologize in advance for the hand waving vagueness, but here's how I think of it.

N=abstract thinker, likes ideas and concepts and big picture S=concrete thinker, likes real things and details

J=likes rules and systems and binary partitions P=thinks in terms of guidelines and heuristics and rules of thumb and grey areas.

Most programmers are Ns, but I have met quite a few DBAs who are Ss. I'm a P (could you tell) although close to the middle. I like to make the joke that Ps are always 5 minutes late, but don't think of that as being late ;)

Hope this helps.