Site Map Providers
Site map providers are the backbone to navigation menus seen throughout websites. They are the connection between the data source and the actual navigational menus that are referenced in a site’s master page. SharePoint 2010 includes several site map providers, which are explained in this section.
For additional information on site map providers, see “Site Map Providers” at http://msdn.microsoft.com/en-us/library/aa478951.aspx.
You can find out-of-the-box SharePoint 2010 site map providers in the Web application web.config file located on the Web front-end server under %SystemDrive%\inetpub\wwwroot\wss\VirtualDirectories\[portnumber]\web.config.
See the book’s resource site for listings of the site map providers ...