chord progression同Diatoinc

chord progression is just simply a succession of chords in a piece of music. e.g. I-IV-V-I, so on.

diatonic chord is chord of the prevailing major or minor keys. e.g. chord IV (FAC) is the diatonic chord of C major, but FAC is not diatonic chord vii of G major, because G major should have F#.