Component Stereotype and Their Design Layers

(3) Business Layer Stereotypes

Java Bean: java beans are reusable software programs that you can develop and assemble easily to create sophisticated applications. In other words, it is a kind of components.

Session Bean: A session bean represents a single client inside the J2EE server. To access an application that is deployed on the server, the client invokes the session bean's methods. The session bean performs work for its client, shielding the client from complexity by executing business tasks inside the server. A session bean is not shared--it may have just one client.

Session Bean (in Business layer) is used by other layers to access the service (maybe provided by Business Component) of Business Layer. It is similar to interface.