Windows 16-bit Environment
All Win16 Applications are supported by a single VDM called WOW (Win16 on Win32). WOW is like a Virtual Windows machine.
The WOW runs on an address space separate from all other user level processes.
A WOW emulates a PC as a DOS VDM does.
WOW converts Win16 APIs and messages to and from Win32.
The Win32 subsystem is used to execute the translated calls.