Windows 8.1 user interface improves on previous Windows 8 features
One change that Microsoft has made in Windows 8.1 is that the operating system's Start screen now supports two new tile sizes. The original Windows 8 tile came in only two sizes. Windows 8.1 supports four sizes. This allows the Start screen to take on an appearance that is more in line with Windows Phone (which was the original basis for the Windows 8 interface).