Diagrams are an easy way to visualise where to put your fingers when learning chords or scales.
These diagrams have six lines representing the strings, and the diagram is oriented as if the guitar is standing up in front of you.
Since the guitar is oriented as if standing up, the thickest string is on the left and the thinnest string is on the right. The nut is usually represented with either a double line or a single bold line, at the top of the diagram.
And the horizontal lines represent the frets.
Dots show where you need to place your left hand fingers.
Often the dots are numbered to show you which fingers you should use; where the 1 is the index-finger, 2 is the middle-finger, 3 is the ring-finger, and 4 is the little finger.
X’s are used to indicate strings which you should not pluck (or should mute). 0’s indicate notes which you should pluck and are to be played ‘open’. This means that you do not need to fret the string with your left hand – just pluck the string without fretting.
When a single finger is used to fret more than one note, it needs to be barred. A barre is represented with a solid line.
Sometimes chord/scale diagrams will indicate positions further up the fret board. In this case the nut is not drawn in. Instead, a normal horizontal fret is drawn, and a roman numeral indicates the fret that the diagram is drawn at.
So this figure means that the index finger is to be placed at the fifth fret, and the ring finger at the seventh fret.
Lastly, chord diagrams are occasionally tipped on their side. When this happens the nut is always on the left, and the string at the top of the diagram is therefore the thinnest string, and the string at the bottom is the thickest. The following two images show the same fingering for the same chord – one diagram is drawn standing up, and the other, lying down.