Essential oils in physical stores are generally sold in specialty stores and beauty shops, and beauty cabinets in big shopping malls are also sold. Essential oil refers to the general name of volatile aromatic substances processed and extracted from aromatic plants or animals. Generally, essential oils are volatile aromatic substances extracted from flowers, leaves, roots, seeds, fruits, barks, resins, wood cores and other parts of plants by steam distillation, cold pressing, liposuction or solvent extraction.