Both hemp and cannabis originate from the Cannabis Sativa plant (although some marijuana originates from the Cannabis Indica plant).
At the core, there is absolutely no difference between CBD obtained from either type of plant, or alternately synthesized in a lab. However, during processing of either variety, the differing methods can significantly alter the final CBD content and product. For example, was the CBD extracted using high-heat? This can decrease the potency and nutritional content of the final product. In hemp CBD, high-heat will destroy the integrity of using the whole plant. Finally, avoid CBD products made from Isolates which, in some cases, have been proven to cause health issues and again may negate the benefits of a whole-plant extract.
Hemp CBD has little to no reported side effects, even under extensive research. It has also been found that CBD naturally decreases the negative side-effects of THC within the mind and body. It effectively targets the CB-1 receptors which THC locks into, and kicks out the THC molecule.
Hemp CBD has been found to be safe for use by nearly everyone, including children, seniors, as well as pregnant and nursing women. Interestingly, hemp CBD has anecdotally been found to successfully treat pets.
Cannabis CBD does have important medicinal applications. Specifically, it has been proven extremely useful for AIDS or cancer patients going through chemotherapy or other harsh traditional treatments. It has also been found to be a natural pain-reliever, and has been assisting people who suffer from Post-Traumatic Stress Disorder.
Hemp CBD on the other hand has far-reaching applications without the side-effects. Anything from boosting overall health for skin, hair and mood to specific applications for serious illnesses like Crohn's disease, Parkinson’s, and some forms of epilepsy, only to name a few. It has been successfully used to treat mood-disorders like depression and anxiety. Finally, and perhaps most excitingly, it has been found to have anti-cancer tendencies, by targeting tumor growth.