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, which helps in reducing boilerplate code. JPA is often used with various implementations, such as Hibernate and EclipseLink, which provide the actual functionality to interact with databases. By using JPA, developers can focus on their application's business logic rather than the complexities of database access, leading to more efficient and maintainable code.