Read original post by Jeremy Likness at MSDN Magazine
The new type of program known as a Windows Store app—optimized to run on Windows 8 devices—has a default view with a full-screen window and no distracting chrome, so the content is the focal point. Windows Store apps support fluid layouts that adapt and scale to a variety of screen sizes and resolutions. They provide a touch-first experience while providing full support for the traditional keyboard and mouse.
Windows Store apps run on a new set of APIs called the Windows Runtime (WinRT). The Windows Runtime exposes components that are built as part of the Windows 8 OS along with third-party components you can develop yourself. [...]