What is "Clean Eating" ?

I think clean eating depends if you talk to different people depending on their goals and current diet they are following (low carb etc) but I think there are a few things that are for the most part "universal"

Non processed foods and refined sugars ( potato chips, french fries, sugary cereals, pop tarts)

Fast food for the most part is not good unless you are really careful with your choices. LIke you could go somewhere and get a grilled chicken salad with dressing on the side.

Sugary anything. Soda, fake healthy drinks like lipton green tea (which has like 30 grams of sugar in it)

Those are the no no's above. Clean foods for the most part are

veggies
complex carbs like brown rice, whole wheat bread (basically carbs with alot of fiber)
lean meats
fruits
nuts
beans

I'm sure other people will chime in. But I hope that gives you an idea.