What are the differences in laws and penalties for drug possession and drug trafficking?

Drug trafficking is a criminal offense that involves the  sale, distribution, manufacturing and smuggling of drugs or controlled substances. It does not necessarily include possession of controlled substances.  So it may well be that your boss can be involved in trafficking even though he does not use drugs himself.  His import-export business unfortunately is a common cover for trafficking in illegal goods, including drugs.  I expect that your boss did a lot of traveling overseas in connection with his business, right?  Trips to acquire the home furnishings and other items that were sold in the business.  Those trips apparently also included arrangements of the importation or distribution of controlled substances, as well– at least according to the government officials who charged him with drug trafficking. Drug trafficking is a federal offense as well as a violation of state laws. Drug trafficking penalties can be quite severe including prison terms of at least four years and very substantial fines even for a first offense.

Of course, everyone is presumed innocent.  Nevertheless, you can consult an attorney who is experienced in criminal defense work to explain to you the potential impact of this situation on your boss, the company and your prospects for continued employment.