An enterprise application is a collection of web application and EJB modules that are configured to work together when deployed to a Java EE application server. The enterprise application contains information about how the modules work together.
The enterprise application also contains information about how the modules work with the application server to which the enterprise application is deployed. For example, if any entity beans use container-managed persistence, the enterprise application tells the application server what transaction services are needed.
An enterprise application has no source files of its own. It only contains deployment descriptors and other configuration files. At compile time, the archive files (JAR files and WAR files) for each of the enterprise application's modules are built and assembled into one Enterprise Archive (EAR) file. This file is deployed to the application server.