Why is it good that cleanser form foam

I learned this somewhere - don't remember - but forming foam when washing your face is a good thing because it means your dead skin cells are being removed.  Basically foam or the bubbles that form are composed of dead skin cells, debris and dirt.  It's just like when you use handsoap to wash your hands.  The more foam, the better. However, don't use handsoap to wash your face. Why? Because then you're dehydrating your face.  That is why you need to moisturize your hands after washing your hand with soap, otherwise your hands will feel rough.  Hand soap is a lot stronger (in terms of cleaning and removing moisture from your hands) than facial wash.