Windows Aero
Short for Authentic, Energetic, Reflective, and Open, Aero is a completely new graphical user interface (GUI) introduced with Windows Vista and found on the Home Premium, Business, Ultimate, and Enterprise Editions (Excluded from Vista Home Basic).
Some of the key features of Windows Aero include a new Glass or translucent appearance to each of the windows as shown in the image to the right. Windows Flip and Flip 3D, which allows you to visually flip through each of the open windows displaying each of the windows and not a simple icon like previous versions of Windows. When minimizing windows the window will visually shrink to the taskbar. Finally, Aero provides a support for higher DPI and smoother performing windows.
Also see: DWM, Operating system definitions, Windows Vista