Storage Spaces

The transition from Windows 7 to Windows 8 introduced a number of new features across various aspects of the operating system. Among these included a greater focus on optimizing the operating system for touchscreen-based devices (such as tablets) and cloud computing.

Windows 8 introduces the new Windows Runtime (WinRT) platform, which can be used to create a new type of application officially known as Windows Store apps and commonly called Metro-style apps. Such apps run within a secure sandbox and share data with other apps through common APIs. WinRT, being a COM-based API, allows for the use of various programming languages to code apps, including C++, C++/CX, C#, Visual Basic .NET, or HTML5 and JavaScript. Metro-style apps are packaged and distributed via APPX, a new file format for package management. Unlike desktop applications, Metro-style apps can be sideloaded, subject to licensing conditions.Windows 8.1 Update allows for sideloading apps on all Windows 8.1 Pro devices joined to an Active Directory domain.

In Windows 8 up to two apps may snap to the side of a widescreen display to allow multi-tasking, forming a sidebar that separates the apps. In Windows 8.1, apps can continually be resized to the desired width. Snapped apps may occupy half of the screen. Large screens allow up to four apps to be snapped. Upon launching an app, Windows allows the user to pick which snapped view the app should open into.

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Wikipedia