Terpenes

Terpenes are aromatic compounds produced by most plants; This is what adds to the therapeutic and some psychoactive benefits of cannabis use.

When you walk into a spa, you expect to smell essential oils in the air; Lavender, Eucalyptus, mint, etc. and all of these scents are expected to place you in a particular mood. Similar to the spa, using certain strains are expected to alter your mood as well.

For example, the terpene limonene (citrus scent ) is found in a number of sativa strains which is heavily associated with mood elevation and energy. Terpenes like pinene (pine scent) are known to be associated with more indica strains producing more of a calming effect. 

Pairing terpenes and cannabinoids together produce a number of effects for users depending on the strain. Hence the reason there are so many different strains to choose from.