Shampoo is used to cleanse and strip the hair of any built-up dirt. Shampoo will help to purify the scalp, allowing the hair to grow in thickness and in strength. Conditioner is usually the second step to hair washing. Conditioner seals in moisture making the hair softer and easier to maintain. Conditioner can be used as a cleanser and a detangler, adding an extra layer of protection to the hair.