Here is the example.
First Let me say what are the entities contributes
to 5 tier  Arch.
1.Client Tier - Browser , Applet , client
application
2.Presentation Tier - Servlets,JSP
3.Business Tier - EJB or some business objects.
4.Integration Tier - JDBC ,
5.Backend Tier - Data bases,JMS etc.

Hope you might have understand the 5 tier
architecture.