WinCE

variety of MsWindows for smaller devices (sub-LapTop, large PDA)

Windows Mobile is best described as a subset of platforms based on Windows CE underpinning. Currently, Pocket Pc (now called Windows Mobile), Smart Phone, and Portable Media Center are the three main platforms under the Windows Mobile Umbrella. Each platform utilizes different components of Windows CE, as well as supplemental features and applications suited for their respective devices. http://en.wikipedia.org/wiki/Windows_CE