An essence is a water-based skincare product containing potent active ingredients.
Its role is to hydrate and nourish whilst preparing the skin to ensure that the products applied after it are well absorbed. Often confused with a toner or serum, an essence is distinct in that it does not perform a cleansing role (as per a toner) and doesn't target specific concerns outside hydration (as per a serum). An essence should be used post-cleansing routine, before application of your serum and / or moisturizer.