Cannabis is a plant that has been used for millennia as medicine.  Like any plant there is a tremendous range in the differences between strains of the plant.  Just like apple trees have a range, Fuji’s to Granny Smiths, so to does cannabis.  The range of strains (cultivars) express themselves with different “chemovar” characteristics.  Today most people recognize the difference in THCa and CBDa production.  It’s important to note that there can be more that 400 different active pharmaceutical ingredients (API’s) in a cannabis plant extraction.