different scopes of managed bean in JSF

Managed beans can have different scopes. They are as:

1. Request
2. Session
3. Application
4. None

A scope of request means that the bean is only available in a single HTTP request. Managed beans can also have session scope, in which case they are available in a single user's HTTP session. A scope of application means that the bean is accessible to all users in the application, across user sessions. Managed beans can also have a scope of none, which means that the managed bean is not stored at any scope, but is created on demand as needed. Additionally, managed beans can have a scope of view, in which case the bean is available until the user navigates to another page. View scoped managed beans are available across Ajax requests.