Here is the information I found. If you notice in the conditioners that work well for your co-poos (V05, suave, Organix, Paul Mitchell) all have glycerin as the ingredient and not veg glycerin. So it seems to me they both do the same thing just made different
Humectant - a non-oily ingredient that attracts moisture from the atmosphere, retards evaporation, and helps hold water. Common ones include glycerine, propylene glycol, sorbitol, hyaluronic acid, urea, and lactic acid.
Emollient- having the power of softening or relaxing, as a medicinal substance; soothing, esp. to the skin: emollient lotions for the face.