In my day to day work I use eclipse 3.3.0 for java development. Eclipse provides a very convenient way to create a dynamic web application (J2EE) and configure it with a server like tomcat or JBoss within eclipse itself. When you deploy your web application in the tomcat separately, you copy the web module directory or the war file to the webapps folder of tomcat. But when you do the same using eclipse, it does not copy any file related to the web application to your tomcat deployment. So when sometime you need to debug your web application, say, by making some temporary changes in JSP files or to see the java files generated for the JSP files, at that time you need to know the actual path where eclipse stores the web application. Eclipse actually creates a tomcat like folder structure in the current workspace. Following is the path of the webapps folder where you can find your web application:
Where Eclipse_Workspace is the current workspace.
If you have not configured the server for eclipse, the org.eclipse.wst.server.core folder remains empty.