What is the difference between hemp-derived & marijuana-derived CBD oil?

So, really, what's the difference between hemp-derived and marijuana-derived cannabidiol (CBD)? There's a lot of chatter, but very few reputable sources have gotten it right.

Dr. Alex Capano, Ananda Hemp's Chief Science Officer, penned an article with Miss Grass to set the record straight. Check it out:  https://www.missgrass.com/debate-hemp-cbd-political-not-scientific/?fbclid=IwAR3QhCLFed9RyeUcE6S8BogSSepRWQc89CDhCcJFDgcqLbexYhYavD9SOq4