What is the difference between a certification and a license?

Another contrast with licensure is that, under a licensing law, practitioners of the licensed occupation must have a license in order to practice. It is involuntary. On the other hand, certification is voluntary. One does not have to be certified in order to practice.

Your license is a order to practice, thats how its different.

a mother eats twice as much to support her growing fetus

limiting sugar intake in a mother with gestational diabetes, switching from diving to swimming.   depending on whether the patient is normal weight, over weight or gain will differ depending on that.