Hey Dragon,
I am very new to this guitar thing too, I've been practicing for 3 days now :D . But I think I can help ya. A chord is totally different from a single note, though it is hard to explain, I'll try :). Okay, a single note is just a single
bum (when I'm saying bum I mean when you hit the guitar string), a chord is putting your left/right hand on the guitar head, holding fingers on the strings (do a google search if you have no idea whatsoever what I'm talking about ), while your doing a chord, you may play different notes and such. So really what I'm saying, is that doing a chord is sort of like making yourself being able to do different notes. Again, if you had no idea what I just said, do a google search for Guitar Lessons, that's how I learned alot :p.
Sincerely, RockZilla