What are UI design patterns?
User interface (UI) design patterns are reusable/recurring components which designers use to solve common problems in user interface design. For example, the breadcrumbs design pattern lets users retrace their steps. Designers can apply them to a broad range of cases, but must adapt each to the specific context of use.
What design patterns are used throughout the .NET framework?
The . NET Framework uses the IEnumerable and IEnumerator interfaces to implement the Iterator pattern.