Entity beans Entity beans are architecturally similar to session beans, but rather than supporting user sessions, they provide access to enterprise data. One entity bean can support multiple concurrent users, and the container synchronizes access with transactions. Entity beans also have primary keys that support finder methods in the home object. A client that knows the primary key of an entity bean can obtain an object reference by invoking the method on the home object. Unlike session beans, home objects for entity beans have a finder method as well as a create method.
Persistence is an essential attribute of entity beans.
This approach is straightforward, but it reduces portability. Container management of persistence means that the bean is free of database calls. The container is informed at installation time about bean data requiring persistence, and the container is responsible for generating code that implements the persistence. This approach allows the bean to be more portable, even to the point of using dissimilar data sources for persistence. However, this approach requires sophisticated functionality in the container.