Hibernate is an open-source Object-Relational Mapping (ORM) framework for Java that simplifies database interactions by mapping Java objects to relational database tables. It automates the process of converting Java objects to database records and vice versa, reducing the need for boilerplate JDBC code. Hibernate supports features like automatic table generation, caching, and querying with HQL (Hibernate Query Language), making it easier to perform database operations. It allows developers to work with Java objects instead of writing complex SQL queries, improving productivity and maintaining a clean separation between application logic and database interactions.