Shampoo is a hair care product that is used to cleanse the hair and scalp of dirt, oil, and other impurities. It is typically applied to wet hair, massaged into the scalp and hair, and then rinsed out with water. Shampoo works by using surfactants, which are compounds that help to break down and remove dirt and oil from the hair. Shampoo also contains other ingredients such as moisturizers, conditioners, and fragrances that can help to improve the texture and appearance of the hair.