Hibernate lets you develop persistent objects following common Java idiom - including association, inheritance, polymorphism, composition and the Java collections framework. Extremely fine-grained, richly typed object models are possible. read more
Hibernate is the most popular ORM framework, once the JPA got introduced hibernate conforms to the JPA specifications. Apart from the basic set of specification that it should follow hibernate provides whole lot of additional stuff. read more
Difference between Spring, Struts and Hibernate are following: Spring is an Application Framework but Struts and hibernate is not. Spring and Hibernate are Light weighted but Struts 2 is not. read more