Not too sure what you are saying in your post but an XML file is usually data which you want to import or export in and out of your database, so for example the XML file contains a list of people in your business, its just a very organized simplistic structure for data which is used mainly by Web applications.
If you are wanting to import xml data then there are 4 methods/type of XML files to import; XML RAW, XML AUTO, XML PATH and XML EXPLICIT.
Hope this helps...