A DTWAIN_SOURCE is a handle to a TWAIN Source.  The DTWAIN_SOURCE is used by the DTWAIN DLL functions that handle TWAIN Sources.


The DTWAIN_SOURCE handle will either be a 32-bit or 64-bit integer, depending on the DTWAIN DLL that is being used (dtwain32(u).dll will return a 32-bit handle, dtwain64(u).dll will return a 64-bit handle).