Enterprise applications use a multi-tiered model, with the tiers grouped by function. When developing enterprise applications in the IDE, you use a web application project to develop the web tier of an enterprise application. The web application can then be added to an enterprise application project. An enterprise application project is a collection of EJB modules and web application modules that are configured to work together when deployed to a Java EE application server.
In the web tier, web applications provide an interface between the client tier that runs on the client machine and the business tier that handles the business logic of the application. Typically, the front-end presentation view that a user accesses via a web browser is provided by a web application.
A web application generally does the following:
When developing a Java EE web application you use web components such as servlets, web service endpoints and JSP and/or JSF pages.
For more infomation about the different tiers in enterprise applications, see Chapter 1 Overview in the Java EE Tutorial: