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

Macintosh II
Mac II

    (Mac II) A version of Apple's Macintosh
   personal computer, released in March 1987, using the
   Motorola 68020 CPU, which runs at a higher clock rate
   than the Motorola 68000 used in the original Mac.  The Mac
   II has a full 32-bit data bus instead of a 16-bit bus.  Mac II
   models have built-in 40 to 160 megabyte hard disks and can
   take up to eight megabytes of RAM (and more as denser memory
   chips arive).

   The Mac II was the first Macintosh to provide a colour
   graphics option, with up to 256 colours on screen at a 640x480
   resolution.  Mac II models are designed for expandability with
   three (Macintosh IIcx) or six (II & IIx) built-in NuBus
   expansion slots for additional peripheral and
   coprocessor boards.

   (1996-05-25)