FBA, or Fulfillment by Amazon, is a service that allows sellers to store their products in Amazon's warehouses. When a customer orders a product, Amazon handles the packing, shipping, and customer service on behalf of the seller. This helps sellers reach a larger audience without managing logistics themselves. Using FBA can enhance a seller's visibility on the Amazon platform, as products fulfilled by Amazon often receive better placement in search results. Additionally, FBA provides access to Amazon Prime customers, which can lead to increased sales and customer loyalty.