Unlike fatty oils, essential oils evaporate completely and leave no trace behind. Aromatic oils are made up of many different ingredients, which are dissolved in fat even though they do not contain any fatty components. The solubility of these oils in water is weak, forming liquid droplets that float on the surface because they are less dense than water.
Essential oils are the main substances responsible for the distinct aroma of plants. These volatile compounds have the ability to evaporate and volatilize under normal conditions.