In case you haven't heard, hemp could literally save the world and certainly didn't deserve to be in the Controlled Substances Act. However, it was kept there through a misinformation and propaganda campaign spearheaded by corporate interests.
The uses for industrial hemp are innumerable but until now, production of hemp was banned by the federal government. Therefore, most hemp products were imported at great cost and prevented valuable jobs in the U.S.
Hemp is simply a variety of Cannabis sativa that is bred for industrial use. Marijuana (C. Sativa, C. Indica or C. Ruderalis) is a name for a strain of C. Sativa that has the frosty, flowering buds where all the resin (cannabin) hangs out. That's the one with the euphoria-inducing tetrahydrocannabinol (THC).