XML – Processor
XML processor generally represented as XProc which processes the XML documents. Sometimes it is called XML promise. usually, every code needs to compiled or interpreted by processor in the background.
In the same way for XML documents Xproc will be the single processing model for all XML documents. This processor just reads the XML document to validate the structure and content inside the XML document.
Finally, it is trying the divide the data from the code and the data will be sent to the application (that might a html web application too.). The data transferred to application will be displayed to end user. If any errors while processing, that will be displaying while showing it in the browser.