As I think, XPS files are like PDF files, but what is the structure od a XPS file? It's like PDF files?
Excerpt:
Behaving more like a ZIP archive file, XPS documents contain all the files necessary to re-create a document on any system. By changing the XPS extension to ZIP, you can view the files related to any XPS document. Specific files include embedded images and fonts so that, if someone doesn't have the same fonts installed on their machine, the XPS Viewer will still render those original fonts, if only for the document.
Portable Document Format (PDF), from Adobe, represents two-dimensional documents in a fixed-layout document that is both device- and resolution-independent. This includes text, forms, images, and 2D vector graphics. Because PDF files do not include information specific to the application or the operating system that created it, PDF files will render the same on any machine.
In short:
Although it shares many similarities with the much more popular Adobe Portable Document Format (PDF), XPS is not a dynamic document format and is designed primarily to transform onscreen content, such as Web sites, into static, printable documents.