Windows 8 and many accompanying devices are launching this month and if you're going to be making a purchase, I highly recommend you understand the differences between the versions of Windows. Microsoft announced months ago that it will have a minimum of three consumer versions (please no jokes about the promises to fix all the bugs too ;-).
While there are some small variations between Windows 8 and Windows 8 Pro, the biggest differences lie between those two — which have a full-featured Start Screen and desktop environments — and Windows RT, which is a mobile environment that runs only Windows Store apps and built-in software.
The story is courtesy of Wired here. Very worthwhile read.