The practice of demand planning consistently leverages one central theme: Plan, Manage and Execute your supply and logistics resources to serve final customer demand. However, the underlying structure for each industry is different. These structures determine the demand to be modeled and planned.
Depending on what industry vertical you are trying to serve, your definition of demand forecasting will be different as well. If you are a retailer, you are trying to forecast your shelf demand at the store level. Your ultimate service measure is the in-store stock levels.