Which statements describe planned and actual revenue for WBS elements?

Planned revenue and actual revenue are two types of revenue for WBS elements in SAP Project System. Planned revenue requires a sales order assigned to a WBS element, which means that the sales order item contains the data for revenue planning, such as quantity, price, and billing plan. Actual revenue is posted via a billing document created from a sales order, which means that the billing document records the delivery of goods or services to a customer and requests payment for them. Reference:https://help.sap.com/doc/0f069b2e08b748f1b480d4c8b46c3c49/100/en-US/6a7a9f0a6e421014e10000000a174cb4.html