cxf xml files

[Rakesh Basani]

Hi guys..

<import resource="classpath:META-INF/cxf/cxf.xml" />
<import resource="classpath:META-INF/cxf/cxf-extension-soap.xml" />
<import resource="classpath:META-INF/cxf/cxf-servlet.xml" />

In cxf.xml file we import above 3 xml files. Why we need these files.. ? Purpose..? And where these files come from..?
And also explain me the use of CXFServlet class in web.xml file..

Thanks in advance..