The D harmonic minor scale has 7 notes: D – E – F – G – A – B♭ – C♯. The harmonic minor is the natural minor with its 7th raised a half step. The gap of three frets between the ♭6 and the 7 gives it its exotic, classical sound, and the raised 7th makes the V chord major, so it pulls strongly back home.
Compared with the D major scale it has ♭3 (F instead of F♯), ♭6 (B♭ instead of B).
The explorer above is set to D harmonic minor: the whole neck is mapped, and you can zoom into any of its 7 positions, change the labels to degrees or fingers, and hear it up, down and in patterns.