NavigationWindow is a window with the ability to navigate between pages. NavigationWindow is one of the navigators in WPF, the other being the Frame. A navigator is the one which supports navigation and navigation history. The highlight of a NavigationWindow is that it can have it’s content as any of the .NET Framework 3.0 objects or HTML contents. "Source" property of the NavigationWindow can be used to set the content of the NavigationWindow.