Windows Presentation Foundation (WPF) is a Windows-only user interface framework in .NET that uses a resolution-independent, vector-based rendering engine to take advantage of modern graphics hardware and enable visually rich desktop applications with features such as XAML markup, a comprehensive control set, data binding, layout, 2D/3D graphics, animation, styles, templates, documents, media, text, and typography, and the ability to incorporate other .NET APIs. WPF exists as a subset of .NET types in the System.Windows namespace and supports familiar programming constructs like instantiating classes, setting properties, calling methods, handling events, plus enhanced constructs such as dependency properties and routed events. Developers build UIs declaratively with XAML and implement behavior in code-behind, simplifying separation of interface and logic while supporting globalization and collaboration between designers and coders.