Difference between web application  and enterprise  application is that web application cab be treated as a small/medium HTTP enabled content serving service that has nothing to do with transactiona, security(to the extend required in case of Banking utilities), and enterprise application has HTTP protocol as well as all sort of Thick protocols such as RMI-IIOP, ORB, Corba IDL etc etc, has transaction, security and lot many more advanced features, suitable for big applications such as banking, insurance, retailers etc etc.

Hope this satifies your query.
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