Dependency property: A property that is backed by a DependencyProperty.
The purpose of dependency properties is to provide a way to compute the value of a property based on the value of other inputs.
These other inputs might include system properties such as themes and user preference, just-in-time property determination mechanisms such as data binding and animations/storyboards, multiple-use templates such as resources and styles, or values known through parent-child relationships with other elements in the element tree.
It has Following capabilities:
The property can be set in a style.
The property can be set through data binding.
The property can be set with a dynamic resource reference.
The property can inherit its value automatically from a parent element in the element tree.
The property can be animated.
The property can report when the previous value of the property has been changed and the property value can be coerced.
The property reports information to WPF, such as whether changing a property value should require the layout system to recompose the visuals for an element.
The property receives support in the WPF Designer for Visual Studio. For example, the property can be edited in the Properties window.
(Content taken from MSDN)
