Streaming refers to a programming model in which XML infosets
Streaming provides high performance (smaller memory footprint, reduced processor requirements).
As you can only see the XML infosets state at one location at a time in the document, you need to know what processing you want to do before reading the XML document.
Streaming models are particularly useful when your application:
the client only gets (pulls) XML data when it explicitly asks for it.
the parser sends the data whether or not the client is ready to use it at that time.