The web.xml Configuration File

When a web application is loaded into a container, its WEB-INF/web.xml file is checked for application meta-data such as:
- Default pages to show,
- Servlets to load, and
- Security restrictions to place on files.

A web.xml file has one top-level XML element:

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
         version="2.4">
...
</web-app>

with configuration elements placed in its scope.