Pavan,
Take a look here :
https://glassfish.dev.java.net/javaee5/ejb/EJB_FAQ.html about specific of the @EJB annotation attributes. For a more generic
EJB 3 tutorial take a look here:
http://docs.jboss.org/ejb3/app-server/tutorial/. If you have more specific questions other than seeking a general explanation to
Java EE 5 DI, I think you will have more useful responses. As you see from previous posts by you on this topic, it is not likely folks will answer very general questions especially things that are documented elsewhere.
Hope it helps,
Reza