Dorian scale for guitar
The Dorian scale, or mode, is the second of the seven musical modes. It is similar to the natural minor except for the raised sixth. The Dorian scale is the minor scale that appears when a major scale is started from the second note (second scale-degree). Thus, a C major scale played from "D" is a D Dorian scale. This is why the term "mode" is more appropriate than "scale".
The D Dorian mode is the same as a C major. So what's the difference? There is no difference; it's the chords that create the magic. Playing a D Dorian scale over a C major chord will sound exactly like playing a C major scale (because they are identical). However, playing a D Dorian scale over a D minor chord will sound "Dorian".