Clean food / Not Clean food
whole wheat pasta / kraft dinner
honey / table sugar
chicken breast / breaded fried chicken burger
Oats / Frosted flakes
fat free sugar free yogurt / jello pudding
whole grain or sprouted grain bread / white bread
etc.
hope that clears it up...
and yes a stack is a combination of supplements that someone could claim work well together...you shouldnt worry about that until you get nutrition down. Only "supplements" you want starting out is whey protein for after your workouts, some gatorade or dextrose for after your workout and some fish oil or flaxseed oil.
Edit: and a multivitamin lol