concept xml file in category itext

This is an excerpt from Manning's book iText in Action, Second Edition.
Generate documents and reports based on data from an XML file or a database
This example was a little bit out of scope for a book about iText. You’ll find more information about HTML to PDF communication (and vice versa) in the JavaScript for Acrobat API Reference. We’ll continue looking at web-related functionality with examples that convert HTML snippets and XML files into a sequence of iText building blocks.
In chapter 8, you injected an XML file containing information about movies into an XFA form. Here you’re going to use the same XML file to create a PDF document from scratch. The XML file is shown on the right in figure 9.12. The result is shown in the Adobe Reader window to the left.