A cream is just a watered-down soap. That does not mean that a cream that you have sitting in your bathroom is the same as that soap sitting next to it. Creams and soaps are usually made by different outfits (some do both, and in such cases the cream may be just a watered-down version of the soap, or it may be slightly altered), and their formulators may choose different formulae and ingredients to tailor their soap or cream to specific requirements. So yes, creams may, on average, contain different ingredients than soaps. However, the fact still remains that from a technological point of view, the only true difference between a (shaving) soap and a (shaving) cream is water content. I.e., to make a soap, you need X water content, and to make a cream, you need Y water content, Y being greater then X.