Object Reference for the Salesforce Platform
jObject Interfaces
An object interface defines the business logic that an object implements. The object
that implements the interface, called the implementor, stores the data and implements the
business logic.
An API that accepts a parameter with an object interface data type can accept any implementor of the object interface. For example, /calculate-price accepts the SalesTransaction object interface. You can use any implementor of SalesTransaction, such as an Order object, in the /calculate-price request.