I'm not sure what the opposite of retail is but it works like this. In business you have wholesale and retail and end user. So the wholesaler keeps the goods in his warehouse in bulk and sells for a cheaper price to the retailer who has his shop in a mall or on a street front. The retailer then puts his markup on the product and sells it to the end user :)

One term often used as the opposite is 'trade sales'. This is often seen (at least in Australia) at businesses which sell to both retail customers and businesses which buy goods for use in their business - eg. hardware stores, plumbers, building supplies etc. Some businesses advertise as selling to 'trade only', meaning they do not sell directly to consumers.

Traditionally, the opposite of "retail" is "wholesale." The entire path by which goods get from the producer to the consumer is called "distribution." The reason I said "traditionally" is that in recent decades, things have changed and gotten complex because of globalization, cheap shipping, electronic payments, credit cards, and the Internet. The traditional distribution system involved several steps. For example, a "wholesaler" might sell to a "jobber," who sold to a "retailer," with fees being charged at every step in the process. The people in the middle of the chain are "middlemen." Distribution is more efficient, and thus cheaper, if you can "cut out the middleman." The fancy word for this is "disintermediation."