If you're a new user to Windows 8, one of the first things you might ask is, "where's the Start menu". Microsoft had to do away with the Start menu and create the Start screen because the world is become more reliant on mobile devices such as smartphones, tablets, and touchscreen laptops.
This new user experience is known as the "Modern" user interface (aka Modern UI), you might hear people still refer to it by its original name which was "Metro" when it was first announced. Microsoft changed the name later, but if you hear it called the "Modern UI" or "Metro" its referring to the same thing.
The traditional Windows metaphor such as the Start Menu (and several others: such as windowed applications, dropdown menus, etc.) don't lend themselves well to the newer mobile device technologies like high resolution touchscreens that don't support a standard keyboard and mouse.
While the modern personal computer/electronics market continues to evolve its becoming less reliant on traditional desktop and laptop technologies (keyboards, mice, track pads, etc.). While its becoming more dependent on gestures, sensors, and high-speed mobile connections.
Windows 8 vs. Windows 8 RT Platforms
Have you ever wondered what's the difference between Windows 8 and Windows 8 RT? It's really easy to get confused trying to understand the distinctions between the two platforms.
Windows 8 runs on x86 compatible CPUs (from Intel and AMD), and can run legacy Windows applications. Windows 8 is designed to run on laptops, desktops, and x86 based tablets (such as the Surface Pro).
Windows 8 RT runs on the Atom CPUs, and doesn't run legacy x86 Windows applications. All the Windows 8 RT applications have to be written for this platform. Windows 8 RT is designed to run on Atom-based hardware (such as the Surface RT). More information.
The Windows 8 RT operating system can't be bought separately it comes with the device you purchase. Also the only way to add applications to Windows 8 RT is by downloading them or purchased in the Windows Store on the device.
Windows 8 features NOT supported in the RT version: Storage Spaces, BitLocker encryption (device encryption is supported instead), Group Policy management or domain support, and Remote Desktop is only available in client mode.
Windows 8 vs. Windows 8 PRO Editions
One of the things that I really appreciate that Microsoft did was create a limited set of Windows 8 editions. Currently there are only two editions available to the general public, Windows 8 and Windows 8 Pro. Technically there is a third edition called Windows 8 Enterprise but this won't be discussed because its only available to large volume Microsoft customers.
Both Windows 8 and Windows 8 Pro share a core set of features, but the Pro edition has a few more enhancements designed for small and medium sized organizations: