Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, including cannabis. Cannabis contains hundreds of terpenes. Terpenes are responsible for the smell and taste of cannabis as well as many of the beneficial properties. Each cannabis strain has a profile comprised of the concentrations and relative proportions of each terpene. For example, Indica is rich in the terpene Myrcene, known to induce relaxation. While Sativa is high in limonene and other terpenes related to alertness and energy, as well as lemon and citrus flavor. Terpenes work in combination with cannabinoids, including THC and CBD, to enhance these effects. The synergy of terpenes and cannabinoids is the Entourage Effect.
Check out Greencamaps Interactive Map of Terpenes; and 15 Terpenes Explained.