An overview of the most common Sales Cloud objects and their relationships
Account, Account Contact Relation, Account Team Member, Asset, Case, Campaign, Campaign Member, Contact, Contract, Contract Contact Role, Forecast Item, Lead, Opportunity, Opportunity Activity, Opportunity Contact Role, Opportunity Forecast Item, Opportunity Product, Opportunity Team Member, Order, Partner, Partner Role, Price Book Entry, Product, Quote, Sales User, Territory, Territory Account
See Salesforce Data Model Notation.