SharePoint XML Viewer

We can use the XML Viewer Web Part to display Extensible Markup Language (XML) and apply Extensible Stylesheet Language Transformations (XSLT) to the XML before the content is displayed.
The content that is displayed in the XML Web Part cannot contain an HTML FORM element.
we can use the XML Web Part to display Structured data from database tables or queries,XML-based documents and XML forms that combine structured and unstructured data, such as weekly status reports or travel expense reports.

There are two ways you can add content to the XML Viewer Web Part

XML and XSL Editors:

we can use these editors to enter or modify XML and XSLT source code. The XML and XSL source editors are plain text editors that are intended for users who have knowledge of XML and XSLT syntax.
Instead of editing the XML and XSLT, you can enter a hyperlink to a text file that contains XML and XSLT source code. The two valid hyperlink protocols.