Essential oils (EOs) are the complex mixture of diverse array of volatile phytoconstituents. These EOs are isolated from every plant part (flowers, leaves, buds, bark, stem, rhizome, and roots) but mainly concentrated in leaves and flowers of the plants. They are primarily produced by specific secretory tissues known as glandular trichomes along with other secretory structures. Different extraction techniques are used for the isolation of EOs, but hydrodistillation and steam distillation are the most employed techniques all around the world. Terpenoids, mainly monoterpenes and sesquiterpenes, low-molecular-weight hydrocarbons, and their oxygenated derivatives, are the key phytoconstituents present in the EOs. Pertaining to the presence of diverse array of bioactive phytoconstituents, EOs are used from the primeval time in different traditional medicinal and healing systems for the cure of variety of ailments. Further, EOs are well known for their variety of biological potential such as antioxidant, cytotoxic, antimicrobial, anticancer, antifungal, antiparasitic, insecticidal, insect repellent, antiinflammatory, pain relievers, mode elevator, etc. Apart from these, now a days, EOs are widely used in various fields and industries like aromatherapy, cosmetics, perfume and fragrance, incense, food preservative, biopesticides, and insecticides industries. Owing to the widespread applications of EOs in day-to-day life, presently the EOs market is growing rapidly. Therefore, the present chapter aimed to discuss the importance of EOs in different fields and current trends in the utilization of EOs particularly in the field of aromatherapy, medicines, and food and nonfood industries.