With its origins in Korean skincare, an emulsion is a highly effective and light-weight, non-sticky base that allows your face to better absorb other, hard-working beauty products in your regime, such as serums and moisturizers. Usually, water-based an emulsion is highly effective at locking in moisture to help retain surface skin hydration and optimal levels of moisturization. If you have oily skin, the water-based formulation is an excellent choice, ditto with sufferers of sensitive skin, as an emulsion has a non-clogging consistency. Emulsions are excellent for brightening the appearance of skin.