What is a GWT Module?
A GWT module is simply an encapsulation of functionality. It shares some similarities with a Java package but is not the same thing. A GWT module is named similarly to a Java package in that it follows the usual dotted-path naming convention. For example, most of the standard GWT modules are located underneath “com.google.gwt” However, the similarity between GWT modules and Java packages ends with this naming convention. A module is defined by an XML descriptor file ending with the extension “.gwt.xml”, and the name of that file determines the name of the module. For example, if you have a file named src/com/mycompany/apps/MyApplication.gwt.xml, then that will create a GWT module named com.mycompany.apps.MyApplication. The contents of the .gwt.xml file specify the precise list of Java classes and other resources that are included in the GWT module.
