Windows 8.1 (successor to Windows 8) was released to the public on October 17, 2013, it was available as an update for Windows 8 customers, or users who do not have a Windows 8 license can download standalone ISO file for clean installation in their PC. Changes and enhancements to software are major differences in Windows 8.1 (compraing with 8), there are not many new features. The deleted start button in Windows 8 was restored in the taskbar, the start screen gets better with new customization options, more default UWP apps are bundled, more apps can be snaped in the screen, and many more changes are included in Windows 8.1.
Microsoft has released an update for Windows 8.1 in April 2014, which includes many new features like UWP apps can now be able to pin to the taskbar, the title bar is available in the UWP app, right-click menu is available for apps listed in the Start Screen etc., the updated version ISO of Windows 8.1 is available separately in the download menu.
Description from Windows 8 (Enterprise)
The Enterprise Edition of Windows 8 is the highest in all editions in terms of features and hardware / software support. It includes all the features of the PRO version, and others, such as Windows To Go, DirectAccess, AppLocker, etc. The 32-bit version of Windows 8 Enterprise Edition supports up to 4 GB RAM, while the 64-bit version supports 512 GB RAM. The Enterprise Edition license is available for Microsoft Volume Licensing customers.
General information from Windows 8
Windows 8 (the successor to Windows 7) was released to the public on October 26, 2012, with a new redesigned user interface that makes it easy to use Windows on tablets and touchscreen devices. The new interface for the operating system was based on Microsoft's 'Metro' design language, which was later continued unchanged in Windows 8.1 and 10. In Windows 8, the Start button was removed from the taskbar, and a new charms bar was added to the right side of the screen. A new start screen was added by changing the Start menu, which includes a list of app tiles with live update option. Microsoft has introduced universal Windows platform apps that are built on the new Windows Runtime (WinRT) library. Universal Windows apps are available in the new Microsoft Store, the Store is pre-installed in the OS. By default, many UWP applications are pre-installed with Windows 8 such as Mail, Messaging, Calendar, Music, Video, Weather, PC settings, and People. All Windows 8 editions are capable of using multilingual user-interface.