Essential oils are complex volatile compounds and their bioactivities have been known and utilized since ancient times in food preservation, perfumery, flavouring and medicine. Essential oils are acceptable because of their unique antibacterial, antifungal, antiviral and antioxidant properties. This review paper focuses on essential oils, its components, extraction methods and their applications. The advances and other applications of essential oils in food, cosmetic and pharmacological industries and the biological effects of essential oils are also conferred.