The D chord on the piano is the combination of the D, F# and A keys played at the same time. This chord is formed by starting at the D note and skipping every other note in the D major scale.
A chord is a group of three to four notes played together, and the letter of the chord indicates which notes are in the chord. The D chord is also known as the D major chord, which is one of the 12 major piano chords. Other less common D chords include D minor, D dominant, D half-diminished and D diminished.