Purpose
The Site List Data Provider (SLDP for short) will access content from SharePoint and present it as XML. It starts with either the current site URL or an identified URL and retrieves sites, lists, folder structures, and their GUIDs from an identified number of levels down from that URL. It can also, through SharePoint, access content from lists within and across site collection through several methods, each providing the fastest possible method of data retrieval.
There are two ways to configure this component: using the List Properties section or the Query Properties section of the web part properties window. If you populate the properties in both sections, it will reference the properties in the List Properties section.
NOTE: When using the List Properties section, the SLDP will leverage an SPView object. By contrast, when using the Query Properties section, the SLDP will leverage an SPSiteDataQuery object. For additional syntax examples, rules and limitations of these objects, search MSDN for these object names along with the version of SharePoint you are using.