D Power Chord (5) (D5)
1+5
Notes in D Power Chord (5)
D (root)A
Inversions
Same notes as D Power Chord (5), with a different chord tone as the lowest note. Useful for smoother movement between chords instead of jumping around the keyboard.
Root position
D in the bass
1st inversion
A in the bass (D5/A)
Play D and A together and you get D Power Chord (5).
Just a root and a fifth, no third at all. That makes it neither major nor minor, which is why rock guitar and simple piano left-hand parts lean on it so much. It sounds strong and neutral, and it leaves room for a singer or another instrument to decide the mood.