A stockout is a situation where a company runs out of stock of a particular product or item, and is unable to fulfill customer demand for that item. Stockouts can occur due to various reasons such as unexpected increase in demand, supply chain disruptions, forecasting errors, or inadequate inventory management. Stockouts can result in lost sales, reduced customer satisfaction, and damage to a company's reputation. Effective inventory management, including the use of safety stock, reorder points, and demand forecasting, can help companies reduce the risk of stockouts and improve their ability to meet customer demand.