Price Books
Price books are a feature of Salesforce. You can use them to set prices for products automatically when you add products to plans, contracts, and billing documents using the BC Line Items Lightning components
If there are multiple active price books in your Salesforce Org, you can select products from different price books. Selecting a different price book has no effect on existing line items on the plan, contract, or billing document.
For more information about price books, see the Salesforce Help.
Price Book Structure Entries
You can create price book structure entries to link your products, price books, and currencies to a pricing structure. This enables you to automatically apply a pricing structure to a product that belongs to the selected price book when you add it to a contract. See Creating Price Book Structure Entries.