A backorder occurs when a customer orders a product that is temporarily out of stock but will be shipped once available. A shipment backorder highlights a gap between supply and demand and directly impacts customer satisfaction. The definition of backorder includes holding customer orders until inventory is replenished, signaling a delay but not a cancellation. In beverage logistics, backorders can happen when high-demand products like popular seltzers or small-batch wines run out, requiring efficient supply chain coordination to fulfill orders promptly.