The Java Persistence API (JPA) is a specification in the Java programming language that provides a way to manage relational data in Java applications. It allows developers to map Java objects to database tables, making it easier to perform operations like creating, reading, updating, and deleting data. JPA simplifies database interactions by using an object-oriented approach. JPA is often used with various implementations, such as Hibernate and EclipseLink, which provide the actual functionality to manage the persistence of data. By using JPA, developers can write less boilerplate code and focus more on the business logic of their applications while ensuring data integrity and consistency.