Microsoft is training sales staff to make sure customers know the difference between Windows RT and the full version of Windows 8, the company told CNET.
Windows RT tablets, including Microsoft's Surface, use power-frugal ARM chips and come with a version of Windows 8 that is not compatible with older Windows software.
Windows 8 and Windows 8 Pro devices -- including an upcoming higher-performance Surface tablet -- are powered by Intel chips and can run the millions of older Windows programs already out there.
Read more at source:
Microsoft training staff to explain Windows 8 versus RT | Microsoft - CNET News
See also:
http://www.eightforums.com/tutorials/5757-compare-windows-8-editions.html