The document describes key concepts related to pricing procedures in SAP for purchase orders: 1. Condition tables define pricing dependencies like discounts, surcharges based on fields in purchase documents. 2. Access sequences are used to search for valid condition records based on a search strategy and field values. 3. Calculation schemas provide the framework and sequence of steps to calculate prices, costs, taxes for purchase orders. 4. Schema groups are used to group vendors and purchasing organizations that use the same calculation schema.