JSF :: Extension Of Pages In URL?

I am working in JSF and I've forgot few of the basics :'I use eclipse IDE to develope JSF projects. When I used to create a JSF file, it's extension is basically .jsp and when I ran that file in server .jsf extension used to be displayed in url. But recently, when I did the same thing I got .jsp extension in browser. in web.xml

when url-pattern is the following, .jsp extension is shown, eg: FileName.jsp

<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>/faces/*</url-pattern>
</servlet-mapping>

but when I change the url-pattern as per following, .jsf extention is shown , eg: FileName.jsf

<servlet-mapping>
<servlet-name>Faces Servlet</servlet-name>
<url-pattern>*.jsf</url-pattern>
</servlet-mapping>

even if I change the url-pattern to abc or xyz, the webpage url is shown in that format. eg: FileName.abc this is the actual scenario to specify extension of a jsf page, or is this an error.