The Free On-line Dictionary of Computing (30 December 2018):

Windows 3.1

    A version of Microsoft Windows with many
   improvements over Windows 3.0, including True Type Fonts,
   Object Linking and Embedding (OLE) and Mouse Trails for
   use with LCD Devices.  It also saw the loss of Real Mode,
   which meant it would no longer run on Intel 8086 processors
   (did anyone ever do this anyway?).

   Sometimes described as "stand-alone Windows", in contrast to
   Windows for Workgroups 3.1.  Windows 3.11 is a free
   bug-fix update.  3.1's successors are Windows 95 and
   Windows NT.

   (1996-07-08)