Hibernate is a powerful, high performance object/relational persistence
and query service. Hibernate lets you develop persistent classes
following object-oriented idiom - including association, inheritance,
polymorphism, composition, and collections. Hibernate allows you to
express queries in its own portable SQL extension (HQL), as well as in
native SQL, or with an object-oriented Criteria and Example API.
Unlike many other persistence solutions, Hibernate does not hide the
power of SQL from you and guarantees that your investment in relational
technology and knowledge is as valid as always.