When shampoo is applied to remove sebum and dirt from your hair and scalp, it also leads to slight swelling of the hair cuticle layer. This is where conditioners show their benefits. They reduce the cuticle swelling, which once again form a tight layer with no gaps or raised cuticles. The hair is now ready for styling and will make it through the day without any serious damage. Properly cleaned and conditioned hair is supple and holds on to its moisture for a dazzling shimmer.