Washing hair removes excess sweat and oil, as well as unwanted products from the hair and scalp. Often hair is washed as part of a shower or bathing with shampoo, a specialized surfactant. The physical action of shampooing makes the grease and dirt become an emulsion that is then rinsed away with the water.
Conditioners are often used after shampooing to smoothen down the cuticle layer of the hair, which can become roughened during the physical process of shampooing. There are two main types of conditioners: intensive conditioners, which enter into the cortex of the hair and help improve the hair's internal condition (also known as Treatment Hair Masks or Hot Oil Treatment Creams or Hammam Zaits); and everyday conditioners ( either rinse off or leaveon), which smoothen the cuticle layer, making the hair shiny, manageable and smooth. Conditioners can also add a physical layer of protection for the hair against physical and environmental damage.