In the diagrams on the left, I am showing some basic information about the theoretical spelling of the "diatonic seventh chords" and "power chords" contained within each key. The larger "highlighted" sections of the fretboard diagrams show what I refer to as "Symmetrical Fingerings". By this I mean that the notes on the "highlighted" adjacent strings are located on the same frets; therefore you would commonly use the same fingers to play the notes on these adjacent strings.