System.Windows

For classes and interfaces used in creating applications.

System.Windows.Controls

For UI content such as buttons, menus, panels and the Viewport 3D (for all 3D content).

System.Windows.Data

For data binding (e.g. linking properties of an object to that of another element)

System.Windows.Input

For all modes of input – for instance, like a mouse – that a user might choose for interaction with an application

System.Windows.Media

For all 2D and 3D graphics classes

System.Windows.Media.Animation

For all 2D and 3D graphics animation classes

System.Windows.Media.Media3D

For classes of objects specific to 3D like lights and meshes

System.Windows.Navigation

For the classes and interfaces used in navigating through an application

System.Windows.Resources

For all the classes that use resources (e.g. this namespace defines properties for things like style that can be accessed by an object)

System.Windows.Shapes

For classes of basic 2D shapes, such as the ellipse, path and rectangle

System.Windows.Serialization

For the conversion of the WPF object model to XAML, and vice versa

Source: David, Jean-Luc, Bill Ryan, Ron DeSerranno and Alexandra Young. "Namespaces." Professional WinFX Beta: Covers "Avalon" Windows Presentation Foundation and "Indigo" Windows Communication Foundation. Wiley Publishing Inc.: Indianapolis, IN. 2005. 6-7.

Background

Defines the brush for the control's background appearance (e.g. a solid colour, an image, an opacity mask)

BorderBrush

Defines the brush for the control's outline

BorderThickness



Determines the thickness of the control's BorderBrush

FontFamily, FontSize, FontStretch, FontStyle, FontWeight

Sets the type of font, size, amount of stretch, the style and the heaviness of the font on the control's text

Foreground


Defines the brush for the control's foreground appearance, which is typically the text on a control

HorizontalContentAlignment and VerticalContentAlignment

How a control's content is aligned on the relevant (e.g. horizontal or vertical) plane

Padding

Determines the amount of space around the control

Cursor

A read/write property to set or get the cursor or to establish cursor representations like MouseEvents

FlowDirection

How a panels elements should flow
For example: TopToBottomThenLeftToRight

Height and Width

Sets the height and width of an element (using double values)

HorizontalAlignment and VerticalAlignment

How a control is aligned on the relevant (e.g. horizontal or vertical) plane

Margin

The space around an element (using double values)
For example:
<Element Margin="Left,Top,Right,Bottom" />

Name

An element's unique identifier to set or get its identity

Style

Sets or gets the style of an object from a resource and is used to set a similar style across similar objects

Tag

Allows developers to associate a WPF object to another object or piece of information in their own application

ToolTip

On MouseOver, this triggers a pop-up window (in order to put a label onto a control)

Source: David, Jean-Luc, Bill Ryan, Ron DeSerranno and Alexandra Young. "FrameworkElement." Professional WinFX Beta: Covers "Avalon" Windows Presentation Foundation and "Indigo" Windows Communication Foundation. Wiley Publishing Inc.: Indianapolis, IN. 2005. 17-19.