The traces of early civilisations show that externally applied cosmetics were an integral part of daily life even then. While this topical mode of application forms the basis of some international regulations, the European Cosmetics Directive defines cosmetics by their intended use, not by their mode of action. Altogether, this legal framework permits a wide spectrum of technologies. Cosmetics can be divided into two broad groups: personal hygiene articles, and products to care for and improve the appearance. Although in physicochemical terms the majority of cosmetics are dispersions, there are also many solutions, some of them colloidal, and mixtures of solids. The cosmetic chemist always chooses the physicochemical state that can best achieve the intended effect.