How is soap and shampoo different? ...
Answers: Soap is a surfactant generally made from lye and potash. Modern soaps are better classified as detergents which utilize different products to acquire the same results lacking the harshness of soap.
Shampoo is a synthetic soap. It works by stripping "sebum" from the hackle (which is the oil that mane follicles produce).
I think the website below will explain it pretty resourcefully:
Shampoo contains less detergent which dries the spine out.