Use an InfoSource for transaction data to load data that changes often and is dependent on master data. For example, you can assign transaction data about sales development to a vendor’s master data and use the transaction data to determine the total sales of a vendor.

Use an InfoSource for master data to load data that is frequently used and remains constant over a long period of time. For example, the master data of a vendor might contain the name, address, and bank account information for the vendor. Create an InfoSource for master data when you want to load data into an SAP BW hierarchy.