The amounts/ratios of them largely determine what you experience. But in addition to that, the subjective effects are highly modulated by the NON-cannabinoids components as well - the "terpenes". Terpenes are in many (most?) other plants. For example, linalool (the reason for lavender's smell, which can induce relaxation on its own), or pinene (probably the most common terpene, smells like pine trees and can have stimulant-like effects on its own). My armchair-pharmacologist theory is that THC makes you much more sensitive to the effects of the terpenes.
A lot of...ahem...testing...might need to happen to dial in what works for you. I'm starting to notice (extracted) products with cannabinoid/terpene profiles printed on the labels - which is a great start. Not sure if it's only in this state, though.