Terpenes and terpenoids (their derivatives including heteroatoms in structure) belong to the largest and diversified class of natural compounds, the vast majority of which occurs in higher plants. They are responsible for the biological activity of essential oils. The latter have found wide application in medicine, agriculture and the production of perfumes and cosmetics. Interest about the structure and properties of the essential oils components is growing because of their application perspective in the sight of new information on biological activity. This review summarizes the data on the main classes of terpenes, their structure, properties and applications, natural sources, extraction, methods of identification and determination of its content in plant raw materials, biological samples, and food products. Up-to-date systematized information in this area allows us to develop more effective ways of their synthesis and further application in agriculture and food industries. Encapsulation is used to increase the stability and solubility in water of terpene-based preparations. Nanoemulsions are one of the most promising encapsulated forms of terpenes. Nanoemulsification makes it possible to expand the terpenes and their derivatives application scope in food storage and in the production of veterinary drugs and modern biopesticides.