Campden a.k.a. potassium metabisulfite is an antioxidant/ preservative, commonly called "sulfites". Most commercial wine labels will have listed it as one of its ingredients. It inhibits the bacteria activity but does not impact the yeast so much.
Potassium sorbate on the other hand is a preservative designed specifically to inhibit yeast reproduction. It's used in white wine, cider, and mead which we want to be sweetened. Sorbate will prevent the yeast from fermenting off these residual sugars and prevent the wine from becoming dry and too alcoholic.