None of the above. I define training as riding with a a structured plan designed to force physiological adaptations like more speed and longer endurance. Generally that means hard days with intervals, a gradually increasing load up to some convenient maximum, and easy days/weeks/months allowing for recovery. That could be outdoors or inside.

You don't need to be too parochial about it (stop lights spaced 8, 12, and 10 minutes apart are as good as 3x10, an extra rest day here and there, a group ride instead of a tempo day) beyond the hard days being enough to force adaptations and rest periods leaving you fresh enough to do that.