The independent hinging of doors on cabinets is the ability to select the hinged side of each door on the cabinet. Otherwise there are pre-set hinge configurations used on a cabinet.
This can be controlled on the Cabinet Details > General Settings page.
Doors are hinged off Cabinet Ends, Mullions or Divisions. If a mullion (or division) is required, because of the selected (independent) hinge side, then one is automatically added.
Example
In this example we are looking at a three (3) door Wall Standard cabinet.