like the title said, what is the difference...

i just recently bought my icewind dale and im already in the iceland thingie in chapter 5. i was wondering if there is any special quest or anything in a single player than in a multiplayer.. is there????

NO differance in multi-layer or single player, you just make your intire team in multi and in single you pick up team members as you go.
I like Multi-player better because I can control everything about my team but I still play single player at times.