Flow Document is a powerful document format from Microsoft, the extension from Flow Document is XAML (Extensible Application Markup Language). Flow Document can include many components including paragraphs, videos, images, and more. These components correspond to elements in markup and objects in procedural code.
In Windows Presentation Foundation (WPF), XAML is used as a user interface markup language to define UI elements, data binding, eventing, and other features. Here's the best source if you want more informations about XAML: Wikipedia and MSDN.
Creating Flow Document using our Flow Document Writer is a step forward because you don't need to know XAML syntax at all. Our Danet Studio provide a Flow Document Writer (Danet Creator), and you can get this Flow Document Writer for free.