posted 17 years ago
JSR 220 explains this very clearly.
A persistence unit is a logical grouping that includes:
� An entity manager factory and its entity managers, together with their configuration information.
� The set of managed classes included in the persistence unit and managed by the entity managers
of the entity manager factory.
� Mapping metadata (in the form of metadata annotations and/or XML metadata) that specifies the mapping of the classes to the database.
