JPA Vs Hibernate

I have come across this question from many of our readers and who ever working on the hibernate framework : What is the difference between Java Persistence API (JPA) and Hibernate ORM Framework. This post simply answer to those who are confusing with JPA and Hibernate difference.

JPA and Hibernate Difference

JPA is a specification for accessing, persisting and managing the data between Java objects and the relational database. As the definition says its API, it is only the specification. There is no implementation for the API. JPA specifies the set of rules and guidelines for developing the interfaces that follows standard. Straight to the point : JPA is just guidelines to implement the Object Relational Mapping (ORM)  and there is no underlying code for the implementation.

Where as, Hibernate is the actual implementation of JPA guidelines. When hibernate implements the JPA specification, this will be certified by the JPA group upon following all the standards mentioned in the specification. For example, JPA guidelines would provide information of mandatory and optional features to be implemented as part of the JPA implementation.

Hibernate is a JPA provider. When there is new changes to the specification, hibernate would release its updated implementation for the JPA specification. Other popular JPA providers are Eclipse Link (Reference Implementation), OpenJPA, etc. You can find the latest release of JPA providers.

In summary, JPA is not an implementation, it will not provide any concrete functionality to your application.  Its purpose is to provide a set of rules and guidelines that can be followed by JPA implementation vendors to create an ORM implementation in a standardized manner.  This allows the underlying JPA implementation to be swapped and for developers to easily transition (think knowledge wise) from one implementation to another.  Hibernate is the most popular JPA provider.