Cannabis use is on the rise in the United States. A 2018 study notes that, while cannabis use among teens has decreased, American adults are increasingly using cannabis on the daily.According to Forbes, the global cannabis industry is estimated to be worth $7.7 billion. It's projected to hit $31.4 billion by 2021.The industry is booming in part because cannabis can be a versatile form of medication. A number of research studies have found that cannabis has the potential to help with a variety of medical conditions, including anxiety, chronic pain, and epilepsy.But, as any recreational or medical marijuana user can tell you, not all cannabis is created equal. Different strains of cannabis produce different effects, and thus can be used for different reasons.