Open XML Paper Specification known as XPS consists of structured XML markup that determnes the layout and visual appearance of each page within the document. The markup language is a subset of XAML which allows it to incorporate vector-graphics in documents. Microsoft developed XPS with the intention of creating an alternative to PDF.
An XPS file is a unicode ZIP archive which use the Open Packging Conventions and contain the files which make up the document. The files includes are an XML markup file, text, embedded fonts, raster images, 2D vector graphics and any DRM (Digital Rights Management) information. These contents can be reviewed by opening in an application that supports ZIP files.
Chrome Firefox Microsoft Internet Explorer Microsoft XPS Viewer Safari
PDF is a file format developed by Adobe Systems for representing documents in a manner that is separate from the original operating system, application or hardware from where it was originally created. A PDF file can be any length, contain any number of fonts and images and is designed to enable the creation and transfer of printer-ready output.
Each PDF file encapsulates a complete description of a 2D document (and, with the advent of Acrobat 3D, embedded 3D documents) that includes the text, fonts, images and 2D vector graphics that compose the document. They do not encode information that is specific to the application software, hardware, or operating system used to create or view the document.