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.