A chord diagram is a schematic representation of a section of the fretboard where the vertical lines are guitar strings and the horizontal lines are frets. The far left vertical line is the sixth string of the guitar, the right vertical line is the first string. The upper horizontal line indicates the upper threshold on the guitar, and the horizontal line below it indicates the first fret.
Sometimes the line marking the upper threshold may be thicker than the others. If the top line is the same thickness as all the others, it may indicate a fret. Continue reading