Terpenes are very complex, so instead of baffling you with science, we will give you a very basic guide to them.
Terpenes are found throughout nature in all sorts of things from food to plants to herbs. Terpenes are what give things a certain smell and taste. For example, the terpene Limonene is as the name suggests has a citrus quality to it. The most obvious place you'd find Limonene is in citrus fruits such as Lemons, Limes and Oranges but it can also be found in peppermint and rosemary.
Terpenes have been found to have their own unique properties, and there are several terpenes found in different strains of cannabis. These are what give the cannabis strains their smell and taste and because of their own unique properties play an important roll in 'The Entourage Effect'
Have a look at the images below. These give you a better understanding of the most common terpenes, their properties and where they are commonly found. Full extract CBD oils will have their own terpene profiles, depending on the plants used to make the oil.