This figure shows how two Java2 Enterprise Edition (J2EE) applications are distributed 
across three tiers: 1) the client tier on the client machine; 2) the middle tier, which 
contains the Web tier and the business logic tier, on the J2EE server machine; and 3) the 
enterprise data tier on the database server machine. The two applications are distributed 
across these tiers in the following way: J2EE application one has three components: 1) An 
application client on the client tier; 2) enterprise JavaBeans in the business logic tier 
on the J2EE server machine; and 3) the database on the enterprise data tier. J2EE 
application two has four components: 1) Dynamic HTML pages on the client tier; 2) 
JavaServer pages (JSPs) and servlets on the Web tier that is located on the J2EE server 
machine; 3) enterprise JavaBeans in the business logic tier on the J2EE server machine; 
and 4)the database on the enterprise data tier.