Your skin is constantly shedding skin cells. When this happens, smoother skin cells push their way up to the skin's surface. However, as you age, the rate at which your body sheds dull and dead skin cells begins to slow down.
In the simplest terms, exfoliation is physically or chemically removing those dead and dulling skin cells. Exfoliating helps speed up your skin's process and helps it to behave younger.
Physical exfoliators work against the top layers of the skin to remove dead, dulling surface cells via rubbing and sloughing. These can include crystals, micro-fine granules and natural beads.
Instead of physically sloughing the dead cells away, chemical exfoliants dissolve the intercellular glue that holds dead skin cells together. Chemical exfoliators penetrate deeper into the skin and can be a great option for skin that has deep congestion, is more resistive, or can't tolerate physically scrubbing their face.
Don't be put off by the word "chemical" – while it may sound negative, it's just a descriptive term for how the ingredients perform.