Hibernate is an object-relational mapping (ORM) library for the Java language, providing a framework for mapping an object-oriented domain model to a traditional relational database. Hibernate solves object-relational impedance mismatch problems by replacing direct persistence-related database accesses with high-level object handling functions.

Hibernate is designed to be flexible in terms of  table schema used, to adapt to use on an existing database. It also has the functionality to create the database from available information.

Hibernate offers a query language data called HQL (Hibernate Query Language), at the same time to build an API queries programmatically (known as “criteria”).

Hibernate for Java can be used in applications Independent Java applications or Java EE, by the component that implements the Hibernate Annotations JPA standard, which is part of this platform.

An interesting point is connecting Hibernate and Liferay. More info about this experience soon!!

Official site: http://www.hibernate.org/