* System.Threading.DispatcherObject class represents on object associated with a "Dispatcher".
* System.Windows.DependencyObject class is the base class for classes that support dependency properties.
* System.Windows.Media.Visual class is the base class for objects that can be rendered to a WPF window or page.
* System.Windows.UIElement class defines core subsystems like Layout, Input, Focus and Events(LIFE).
* System.Windows.FrameworkElement introduces data binding and data templates, styles and animation.
* System.Windows.Controls.Control class adds a feature called templating. This is the base class for all the controls that the user interacts with.
* System.Windows.Controls.ContentControl can hold a single nested element.
Source: Interview | Asked In: Many Interviews |