Hibernate
In plain terms
A popular ORM framework for Java.
Going deeper
Hibernate maps Java objects to relational tables, handling persistence so developers work with objects, not SQL. It implements the JPA standard.
Under the hood
Manages caching, lazy loading, and relationships; the N+1 problem and complexity are common pitfalls.
Examples
Java/Spring apps, JPA, enterprise persistence, object-relational mapping.
Think of it like...
Like an automatic clerk filing your Java objects into database rows and back.