>I haven't found any definitive answer to what is "actually" happening under the hood. From what I can tell, XML is what is getting passed. The structure of the DataSet object was centered around XML.
>
>><<
>>You can work with the DataSet objects as XML documents.
>><<
>>
>>So is that what happens? Even if it looks like I am passing a dataset object, in reality, xml is what actually gets passed??

Some clarifications after reviewing this thread. If you pass a DataSet object, it is sent as a serialized binary stream of data, not XML. This allows the data to be more compact which increases performance. Under the hood, there are mechanisms which allow a DataSet object to be converted to and from XML documents easily and quickly.

Developers should avoid thinking that a DataSet object is an XML document or string since it not. An XML document must be a string which adheres to the W3C rules of an XML document with proper headers, elements, structure, etc. An XML document object is an object which has been created based on an XML string, file, URL source, etc. An XML document may be based on a DOM (W3C document object model for XML), a custom XML API interface, .NET classes found in system.xml, etc. Just think of a DataSet object as something that can be created from XML or exported to XML easily and quickly. VFP 7.0 is not compatible with .NET DataSet objects directly so XML strings are required for interop, as would be the case for many COM or external applications interfacing via XML Web services COM/.NET interop.