Windows 8 or Windows RT?

At the beginning, I got confused about Windows 8 and Windows RT.  Do you make it clear that their differences?

Windows 8 is based on the Intel processor, however Windows RT is based on the ARM processor.

However Windows RT has some limitation from Windows 8.

It can't run Adobe photoshop or some games which can run fluently on Windows 7 or 8. Even it can not run the apps that Microsoft itself made: such as windows media player and Outlook.

All the apps can only run through the Windows Runtime Library which is called Metro. The normal Win32 API can not run on Windows RT.

So when you want to try on the new Windows RT devices, be sure that you can get through with all these limitation.