The main difference between chicken stock and the chicken base is in the thickness between the two.
The chicken base is thicker than chicken stock and is darker in color and is more like beef broth.
The chicken stock is thinner than chicken base and is usually lighter in color than chicken base is.
The chicken base is mainly used for making sauces, skillet dinners, or stews while the chicken stock is used for other recipes.
So when your recipe calls for chicken stock you should use chicken stock and when your recipe calls for chicken base you should use chicken base.
Otherwise the recipes won't turn out as good.