Business Object Components
A business object, which a service implements, is a hierarchy of service data objects. Each service data object is a logical entity that consists of attributes, referred to as service data object attributes. This structure encompasses the required contextual and dependent information, so it's not necessary to invoke multiple services.
For example, a Sales Lead service is defined on the Sales Lead
            business object, which consists of service data objects such as Sales Lead contacts,
            Sales Lead products, and the Sales Lead data object itself. Each service data object
            contains attributes that define the object. Name, DealAmount, and Score are example attributes that define the
            Sales Lead service data object. These attributes may have a built-in data type such as
            long and string, or may have a complex data type that corresponds to another service
            data object. For more information, see Business Object Service Data
                Types.
The following diagram shows the service data objects as rectangles and the relationship between the data objects as lines. The Sales Lead service data object is the top-level entity, and Note, Sales Lead Contacts, Sales Lead Products, and Sales Lead Resources are the child entities. The Note child entity has Note Descriptive Flexfields as the grandchild entity.
