Often, we misinterpret the meaning behind these terms and mistake skin oil for hydration. Oil or sebum produced by our skin is nothing but a lipid that is composed of fatty acids. These oils, present in the skin, surround the outermost layer of the skin and provide nourishment. This is essential to protect and repair the skin’s natural barrier function. Whereas, hydration refers to the presence of water in the skin’s layers – dermis and epidermis – which maintains plumpness and elasticity. Moisturizers are a combination of both they nourish the skin as well as keep up the water levels for longer period of time.