Short and simple, terpenes are an organic compound that grow on the hemp plant.
They are tiny compounds that give the plant it's scent and flavor.
For example, your Christmas tree smells like pine because of the terpenes in the tree! The lovely aroma you get walking through a lavender field is because of the terpenes in the lavender flowers!
Terpenes can be extracted from the hemp plant individually, then added back into the CBD formula to give a desired effect, smell, and flavor. These natural terpenes mixed with selected essential oils can enhance the therapeutic effects.