title: Diff between @SessionScoped (CDI) and @Stateful (Java EE)
body: <p>I learned that CDI Beans can be used in different web-application-based scopes (only there, right?). For example: @RequestScoped, @SessionScoped and so on. @SessionScoped hold the data in a managed bean over the complete browser-session. That sounds quiet logically, because the annotations name describes what it does.
  However - now I had a closer look at EJB session beans. So far I know, that such a been could have one of three states: @Stateless, @Stateful and @Singleton.
  For me, it looks like there is a direct comparability between those and the annotations of a CDI bean: @RequestScoped --> @Stateless, @SessionScoped --> @Stateful , @ApplicationScoped --> @Singleton.
  But since I was studying some examples, I found a bean which includes both the @Stateful and the @SessionScoped annotation.
  I looked for an explaination - but I did not find any answer which was understandable. So, what exactly is the difference? Why do I have to use both annotations? Thank you.</p>