I had the same research and seminar on "Enterprise Computing"
and "Enterprise Applications" (in March 2000) here are some of them:

1)
The term enterprise  implies highly scalable, highly available,
highly reliable, highly secure,
transactional, distributed applications. Enterprise applications
require access to a variety
of infrastructure services, such asdistributed communication
services, naming and directory
services, transaction services, messaging services, data access and
persistence services,
and resource-sharing services. These infrastructure services are
frequently implemented on
different platforms using different products and technologies,
making it difficult to build portable
enterprise-class application  systems.

2)
The term 'enterprise' implies extremely robust computing. Enterprise
applications support core business operations, and any failure of
these applications causes an interruption in business operations.


3)
-Extremely robust application environment
-Supporting wide distribution
-Massive scalability
-Non-stop availability
-Bulletproof reliability
-Handling many concurrent client request and high number of
complicated transactions

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.
more at http://www.ideas2work.com/share-knowledge.php

An enterprise  application normally consist on several
things:
a) Database data
b) Objects to access that database
c) Business Logic to use that data
d) Routing objects to select the proper BL objects
e) presentation objects

Since presentation objects in modern Enterprise apps
are web-based you ususally wnat them in a different
machine to assure the security of the other layers, so
you will have distribuited objects called by protocols
such RMI or IIOP. Java enterprise applications are
usually done with the J2EE framework and thinked with
the J2EE patterns guide, so you will have several kind
of objects:
a) JSPs and servlets for web requesting. Some servlets
usually are "Controllers" that routes the web request
to the propper presentation responder (JSP or another
servlet) they are called Front Controllers
b) Facades are used to hide Business logic to
presentation layers, ideally they don't have any logic
and are forwarders between JSPs/servlets and session
beans who do have business logic in the same or
different server.
c) Session beans are used to have business logic
centralized and they usually are in the same server as
entities wich are normally used to do one register
seleccions or writting ops to the database. The
"Container" (server that handles Entity and sessiion
beans) is incharge to access the database via hits own
connection pool in order to prevent bad practices on
database access programming like the lack of commmits
or the lack of connection clossed.
d) Value Objects are simple  classes that are used to
transport entity data to the facades or beyond,
reducing network consumption.
e) DAOs are required when you need a collection of
Value Objects (multiple row selects for example).
And there are many other java patterns that help to
provide a stable and good Enterprise application  with
the Java framework.

The following paragraph is my own opinion and is not a classic definition.

Enterprise application  are the applications which are used in enterprises or has the behavior like them .As you know enterprise  means “A business organization” so a business organizations may need a system with different subsystems serving different departments of the organization. Such an application can be developed with an architecture that best matches functional and non-functional requirements of the project and the point is that there is no fixed architecture for this.
Technically Enterprise Applications are often multi-user systems consisting of two or more interacting subsystems. Generally such applications have transaction concurrency, user load, better subsystem encapsulation, subsystem interaction issues………