"Botanically, industrial hemp and marijuana are from the same species of plant, Cannabis sativa, but from different varieties or cultivars that have been bred for different uses.2 However, industrial hemp and marijuana are genetically distinct forms of cannabis3 that are distinguished by their use, chemical makeup, and differing cultivation practices in production. While marijuana generally refers to the psychotropic drug (whether used for medicinal or recreational purposes), industrial hemp is cultivated for use in the production of a wide range of products, including foods and beverages, personal care products, nutritional supplements, fabrics and textiles, paper, construction materials, and other manufactured goods.

"Both hemp and marijuana also have separate definitions in statute. While marijuana is defined in U.S. drug laws, Congress established a statutory definition for industrial hemp as “the plant Cannabis sativa L. and any part of such plant, whether growing or not, with a delta-9 tetrahydrocannabinol concentration of not more than 0.3 percent on a dry weight basis” as part of the 2014 farm bill.4 Hemp is generally characterized by plants that are low in delta-9 tetrahydrocannabinol (delta-9 THC), the dominant psychotrophic ingredient in Cannabis sativa.5

"For more background information, see CRS Report R44742, Defining “Industrial Hemp”: A Fact Sheet. However, joint guidance issued in August 2016 by DEA, USDA, and the Food and Drug Administration (FDA) suggests that there continues to be questions about what constitutes industrial hemp and its oversight under federal law."

Source

Johnson, Renée. Hemp As An Agricultural Commodity. Congressional Research Service. Washington, DC: Library of Congress, June 28, 2018.