Exfoliation is the process of removing dead skin cells, either physically or chemically.
Physical exfoliants, like a facial scrub or exfoliating mitt, work by manually removing dead skin with a rough surface.
Chemical exfoliants, as the name suggests, use chemicals to break the bonds between skin cells and remove dead skin.
Examples of chemical exfoliants include alpha hydroxy acids (AHAs), such as glycolic acid, and beta hydroxy acids (BHAs) such as salicylic acid.