Shampoo is a hair care product designed to keep your hair clean and soft. Your skin produces sebum, a greasy substance, to coat and protect hair and the hair follicle. Sebum coats the cuticle or outer keratin coat of each hair strand, giving it a healthy shine. However, sebum also makes your hair look dirty. An accumulation of it causes hair strands to stick together, making your locks look dull and greasy. Dust, pollen, and other particles are attracted to the sebum and stick to it. Sebum is hydrophobic. It waterproofs your skin and hair. You can rinse away salt and skin flakes, but oils and sebum are untouched by water, no matter how much you use. This is where Shampoo's come in as they will wash away the sebum to make your hair look clean and soft !