The Sales Order object and its relationships with the Product conceptual entity as well as Opportunity, Account, Account Contact, and other objects
Account, Account Contact, Brand, Bundle Product, Contact Point Address, Contact Point Email, Contact Point Phone, Goods Product, Individual, Lead, Master Product, Opportunity, Opportunity Product, Order Delivery Method, Product Catalog, Product Category, Product Category Product, Sales Order, Sales Order Product
See Salesforce Data Model Notation.