下面是Wikipeida里面关于Hibernate的定义
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 free as open source software that is distributed under the GNU Lesser General Public License.
简单来说Hibernate就是将数据库里面的表映射成JAVA的对象。在程序里面对数据库的操作变成对JAVA对象的操作。同时Hibernate是一个开源框架。