|Apache Struts 2 Documentation > Home > Guides > Core Developers Guide > Configuration Elements|
A web application uses a deployment descriptor to initialize resources like servlets and taglibs. The deployment descriptor is formatted as a XML document and named web.xml.
Likewise, the framework uses a configuration file to initialize its own resources. These resources include:
At runtime, there is a single configuration for an application. Prior to runtime, the configuration is defined through one or more XML documents, including the default struts.xml document. There are several elements that can be configured, including packages, namespaces, includes, actions, results, interceptors, and exceptions.
See struts.xml for a working example.