Essential oils are not single chemical compounds but complex mixtures of volatile organic compounds extracted from plants, primarily consisting of terpenes, terpenoids, phenols, and other aromatic molecules. They are obtained via distillation or cold pressing and are used in food, cosmetics, and aromatherapy. Properties such as boiling point, melting point, and exact solubility vary widely depending on the source plant and composition. They are generally lipophilic and evaporate readily at room temperature. No single IUPAC name, formula, or molecular weight applies.