The natural minor to any major scale is the sixth degree of any given major scale. A parallel minor scale shares the same starting tone but follows it'sits own natural minor scale and would have a different natural relative major.
In doing the major scale itself, there are then the modes...
So yes, a mode is simply playing from one note to that same exact note in the order that it falls within that key. D to a D in the key of C is your Dorian minor mode. G to to a G in the key of C is your mixolydian mode, or the mode that will fit perfectly over a Dominant chord(a dominant chord unaltered).