The Java EE 6 Tutorial, Volume I

About Managed Beans

A managed bean is a bean that is implemented by a Java class, which is called its bean class. A top-level Java class is a managed bean if it is defined to be a managed bean by any other Java EE technology specification (for example, the JavaServer Faces technology specification), or if it meets all of the following conditions:

No special declaration, such as an annotation, is required to define a managed bean.