JPA provides object/relation mapping capabilities to enable mapping between relational database tables and Java objects in order to ease persistence in Java applications. JPA consists of the following features:

• A query language to enable querying from relational database tables in order to retrieve Java objects
• A JPA Criteria API, which can be used to generate queries dynamically
• A set of metadata defined with XML Java annotations in order to successfully map relational database table columns to Java object fields

JPA is not an actual implementation of the preceding features but merely defines the specification. Third-party vendors can perform their own implementation that conforms to the specification. The most popular third-party implementations that support JPA are Hibernate and EclipseLink. 

JPA 1.0 was released in 2006 as part of Java Community Process JSR 220. Its latest version is JPA 2.2, which was released in 2017. JPA has made persistence easier and standardized for developers while allowing transactions and data consistency. This has helped a lot, making JPA famous among developers.