CBD is the cannabinoid called Cannabidiol.  It is found in the plant Cannabis Sativa L.  Cannabis Sativa L is classified as hemp when delta 9 THC is below .3%, and it was legalized with the 2014 farm bill. CBD is present in marijuana as well.  Historically, CBD diminished as the cannabis plant was bred for high THC content.  CBD has made a comeback recently.  Genetics now target very high CBD and low THC cultivars.  Many marijuana cultivars are also now featuring more evenly blended CBD to THC content.