In most cases, all of the resources that you need to create for your Web
application are developed during Web site or Web page design; however, there
are additional resources that you may need to include in your Web project
if you are using more advanced Web technologies in your application.
These Web resources are not typical Web page files, and are often not the
resources that you consider part of the final Web site. For example, tag libraries
and Java™ resources,
such as JAR files, are resources you might need to include in your Web project.
In fact, even the WAR file itself could be considered a Web resource, if
you consider importing or exporting the resource.