For Consumers: Windows 8/8.1 Standard
Windows 8/8.1 is the consumer version of the OS. It excludes many business-related features such as drive encryption, group policy, and virtualization; however, you have access to the Windows Store, Live Tiles, Remote Desktop Client, VPN Client, and other features.
For Small Businesses: Windows 8/8.1 Pro
Windows 8 Pro is made for businesses and technology enthusiasts. It includes everything found in the standard edition plus features such as BitLocker encryption, PC virtualization, domain connectivity, and PC management. It’s what you’d expect from Windows if you’re operating in a professional environment.
For Large Scale Corporate Deployments: Windows 8/8.1 Enterprise
Windows 8/8.1 Enterprise includes everything that Windows 8 Pro has, but it is geared towards enterprise customers with Software Assurance agreements. This version is no longer supported by Microsoft and has been supplanted by the enterprise edition of Windows 10.
For Mobile Users: Windows 8/8.1 RT
Windows 8/8.1 RT (also called Windows Runtime or WinRT) is specifically designed for ARM-based devices. ARM is a processor architecture used in devices like mobile phones, tablets, and some computers. The nice thing about Windows RT is that it offers device-level encryption and the touch-enhanced Office suite as part of the operating system, so you don’t have to buy a copy of Office or worry about data exposure. The downside is that Windows RT runs a hobbled version of the desktop that can only run the Office suite and Internet Explorer.
Can I Upgrade to Windows 8?
Windows 8/8.1 can be installed as an upgrade from Windows 7 Starter, Home Basic, and Home Premium. Users who want to upgrade to 8 Pro need to have Windows 7 Professional or Windows 7 Ultimate. If you have Windows Vista or XP, chances are you probably need a new PC anyway. Newer PCs come packaged with Windows 10, which is probably a better choice than Windows 8.1.