Scented oils obtained from natural sources are called essential oils. They are odoriferous bodies of an oily nature, obtained from herbal sources, generally liquid (sometimes semi-solid or solid), at ordinary temperatures and volatile without decomposition. These are the constituents of plants generally volatile in steam. Most important oils that have a good demand presently are: lemon grass oil, rose oil, ginger oil, clove oil, citronella oil, geranium oil, palmarosa oil, eucalyptus oil, mint oil, vetiver oil, jasmine oil, lavender oil, cinnamon oil etc. The cultivation of herbs depends upon the soil type, rainfall, climate, irrigation and geographical conditions.

The extraction of oil from the herb or the flower was generally through steam distillation using water. Later, solvent extraction was introduced, that increased the yield and produced better quality essential oil. Essential oils are used in toiletries and tooth paste, and food products like confectionery, chocolate, ice cream and pharmaceuticals. They are used in perfumes, cosmetics and soaps, and to flavour food and drink, and for adding scents to incense and household cleaning products. India has also developed good cultivation techniques through massive research work. The essential oil industry is thus very well grown in India and a considerable amount of foreign exchange is generated by exports.