#1 – What is WPF?

WPF (Windows Presentation Foundation) is a .NET class library that allows building graphically rich client programs that run on Windows.  WPF applications can either run as separate windowed programs or can run inside a web browser.

WPF renders graphical elements using 3D vector-based graphics, independent of screen resolution.  WPF uses DirectX for rendering graphical elements, which allows it to take advantage of hardware acceleration.  If hardware acceleration is not available, WPF renders elements using software, rather than hardware.

WPF replaces Windows Forms as a programming environment for creating client applications on Windows.