One option is a full spectrum CBD, also sometimes called whole plant CBD, full spectrum hemp extract, or broad spectrum CBD, and the other is a CBD isolate. What’s the difference?
A full spectrum CBD oil is called full spectrum because, in addition to containing CBD, it also contains other health-promoting cannabinoids found within the cannabis plant.
A few of these cannabinoids are cannabichromene (CBC), cannabigerol (CBG), cannabinol (CBN), and perhaps the most well-known cannabinoid of all, tetrahydrocannabinol (THC). THC is the psychoactive part of the marijuana plant, making it the one cannabinoid that causes many people concern.
This is fair since taking THC can cause you to fail a drug test, ultimately costing you your job. That said, it should be noted that full spectrum hemp oil products either contain no THC at all or only trace amounts of THC. Therefore, taking a full spectrum CBD oil will not make you feel high. However we do not recommend taking any full spectrum products if you will be required to take a drug test. Even though legal full spectrum CBD has very small amounts of THC it could cause you to fail the drug test.
Full spectrum CBD oil also contains other good-for-you cannabinoid acids such as cannabigerolic acid (CBGA), cannabidiolic acid (CBDA), and cannabigerovarinic acid (CBGVA), just to name a few. It has terpenes, terpenoids, and flavonoids. 
Oils that are CBD isolates, on the other hand, contain only one cannabinoid, and that is CBD. But isn’t CBD enough if your goal is to achieve relief that this particular hemp extract has been found to help?
The short answer is not always, and the reason for this has to do with something called the entourage effect.
Since full spectrum hemp oil contains multiple cannabinoids and several other healthy substances collected during the whole plant extraction process, all of these “ingredients” work together in way that makes them more powerful as a combined unit than each is on its own.
Think of it like combining spices and herbs when you cook. For instance, even though you may enjoy the taste of garlic, basil, and oregano on their own, add them together and you are able to create an Italian meal that makes your taste buds sing.
The same principle applies with regard to CBD and all of the other cannabinoids found within a full spectrum extract. By creating CBD products that contain all of these things together in one unit, users gain the therapeutic benefits. Benefits that aren’t as strong with a CBD isolate.
Some studies have found that full spectrum CBD oil’s interaction with the endocannabinoid system has been linked to improved responses for individuals engaged in physical therapy or rehabilitation for musculoskeletal or nervous system issues. Furthermore, in cases such as these, full spectrum extract provides a “more linear dose-dependent therapeutic response” than CBD isolates, even when those isolates are 99 percent CBD. 
Other studies have noted that CBD and THC combined can be beneficial for individuals. 
Using CBD products that contain numerous cannabinoids, terpenes, and flavonoids offers other benefits as well.
Additionally, when purchasing high-quality CBD tinctures that are non-genetically modified (non-GMO), you don’t have to worry about the nasty side effects commonly associated with taking in pesticides or other unsafe chemicals.
The bottom line is, if you want to enjoy the full effects of CBD oil, choose a full spectrum CBD product because this particular option contains a number of cannabinoids and hemp extracts that, together, can offer a higher level of relief.
 Kogan, N & Mechoulam, R. “Cannabinoids in health and disease.” Dialogues in Clinical Neuroscience. Dec 2007; 9(4): 413-430. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3202504/
 Lopez, H. “Potential Role of Hemp-Derived Full-Spectrum CBD Oil in Rehabilitation and Physical Therapy.” Elite Learning. Sep 5, 2018. https://www.elitecme.com/resource-center/rehabilitation-therapy/physical-therapy/potential-role-of-hemp-derived-full-spectrum-cbd-oil-in-rehabilitation-and-physical-therapy/
 Johnson, J et al. “Multicenter, Double-Blind, Randomized, Placebo-Controlled, Parallel-Group Study of the Efficacy, Safety, and Tolerability of THC:CBD Extract and THC Extract in Patients with Intractable Cancer-Related Pain.” Journal of Pain and Symptom Management. Feb 2010; 39(2): 167-179. doi: 10.1016/j.jpainsymman.2009.06.008. https://www.sciencedirect.com/science/article/abs/pii/S0885392409007878