EJB 3.0 Persistence API Documentation

Packages 
Package Description
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.