What Are Terpenes?
Terpenes are molecules created by many different kinds of plants, including the cannabis plant. When found in the cannabis plant they give each strain its unique scents and flavors. Combined with hundreds of cannabinoid molecules, terpenes also contribute to each strain's unique psychoactive and physiological effects. This is called the "entourage effect." Terpenes can also be added to cannabis extracts such as CBD oil to impart desired scents and flavors on the product.
Leafly summarizes what terpenes are very well:
Secreted in the same glands that produce cannabinoids like THC and CBD, terpenes are the pungent oils that color cannabis varieties with distinctive flavors like citrus, berry, mint, and pine.
Not unlike other strong-smelling plants and flowers, the development of terpenes in cannabis began for adaptive purposes: to repel predators and lure pollinators. There are many factors that influence a plant’s development of terpenes, including climate, weather, age and maturation, fertilizers, soil type, and even the time of day.
Here is an infographic, also from Leafly, that neatly "outlines properties of six common cannabis terpenes along with a few strains that tend to express notable levels of each."
Check out all the products at Diamond CBD that include a wide variety of terpene flavors.