The Harmonic Minor scale has nearly all the same notes as the natural minor scale except for the seventh degree.
In the harmonic minor scale the seventh note is major rather than minor which makes it different from other minor scales.This raised seventh acts as a leading tone which resolves to the root note of the key.
The main role of the harmonic minor scale is to create harmonies (chords) for minor progressions. However, the seven modes of the harmonic minor can be used for improvising over some unusual chords.
For me, the sound of the harmonic minor scale always conjures images of epic dragon battles and unnaturally fast guitar wizards with frilly shirts.