Essential oils are concentrated liquids that do not dissolve in or mix with water and contains volatile aroma compounds, extracted from the plants. Also known as volatile oils, or ethereal oils, essential oils are not just oils in the strict sense and carry a unique scent, or essence, of the natural source from which they are extracted. Generally aromatic essential oils are extracted by the process of distillation, or often by using steam distillation, or expression or solvent extraction. These pure essential oils are used for varied purposes in industries like perfumery, soaps, cosmetics and for flavouring food and drinks. In addition, these oils also find usage in incense sticks for adding scents and in household cleaning products.