About TopLink Mapping Types

In the TopLink Mapping editor, mappings define how an object's attributes are represented in the database.

Direct mappings define how a persistent object refers to objects that do not have descriptors (for example, the JDK classes and primitives). See "Working with Direct Mappings" for details.
Relationship mappings define how a persistent object refers to other persistent objects. See "Working with Relationship Mappings" for details.