Sun Microsystems Persistence API Reference

Java EE 5 Platform Packages

javax.persistence	The javax.persistence package contains the classes and interfaces that define the contracts between a persistence provider and the managed classes and the clients of the Java Persistence API.
javax.persistence.spi	The javax.persistence.spi package defines the classes and interfaces that are implemented by the persistence provider and the Java EE container for use by the container, provider, and/or Persistence bootstrap class in deployment and bootstrapping.