In Windows Presentation Foundation (WPF), attached properties are a specialized form of dependency property that does not have the conventional property "wrapper".
An attached property is intended to be used as a type of global property that is settable on any object. It allows different child elements to specify unique values for a property that is actually defined in a parent element (Grid.Row and Grid.Column are an example of frequenly used attached dependency properties).
General information: Attached Properties Overview
