The B harmonic minor scale has 7 notes: B – C♯ – D – E – F♯ – G – A♯. 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 B major scale it has ♭3 (D instead of D♯), ♭6 (G instead of G♯).
The explorer above is set to B 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.