what is amazon fulfillment refers to Amazon’s system for storing, picking, packing, and shipping products on behalf of sellers. This service is part of the Fulfillment by Amazon (FBA) program and includes customer service and returns handling. Sellers ship their inventory to Amazon’s fulfillment centers, and Amazon takes care of the rest. This allows sellers to scale operations quickly, benefit from Amazon’s trusted delivery network, and reach more customers with Prime-eligible listings.