Demand planning is a process of forecasting and managing the demand for a product or service over a certain period of time. It involves analyzing historical sales data, market trends, and other factors to create a forecast of the expected demand for a particular product or service in the future. Demand planning helps businesses to anticipate customer demand and align their production, inventory, and supply chain operations accordingly. By accurately forecasting demand, businesses can optimize their resources, reduce costs, improve customer satisfaction, and increase their overall profitability.