CBD is one of many compounds found in hemp. Full Spectrum CBD is extracted to keep as many of these other compounds (cannabinoids & terpenes) in the oil. This also includes trace (less than .3%) amounts of THC. Broad Spectrum CBD is like decaf coffee; it is full spectrum CBD oil run through another extraction process that removes all traces of THC. CBD Isolate is CBD oil that has been reduced and extracted down to just the CBD molecule. With CBD Isolate you get nothing more and nothing less than pure CBD.