Managed Bean is a regular Java Bean class registered with JSF. In other words, Managed Beans is a java bean managed by JSF framework.
1: The managed bean contains the getter and setter methods, business logic or even a backing bean (a bean contains all the HTML form value).
2: Managed beans works as Model for UI component.
3: Managed Bean can be accessed from JSF page.
4: In JSF 1.2,a managed bean had to register it in JSF configuration file such as faces-config.xml.
5: From JSF 2.0 onwards, Managed beans can be easily registered using annotations. This approach keeps beans and there registration at one place and it becomes easier to manage.