How to Read Guitar Chord Diagrams
Guitar Chord Diagrams show the notes used to play a guitar chord and their location on the fretboard of the guitar.
The thick line at the top of the chord diagram represents the nut (a piece of plastic or other material at the top of the neck that holds the strings) of the guitar. The vertical lines in the chord diagram represent the guitar strings, and the horizontal lines represent the guitar frets.
View guitar chord diagrams as if you were facing the fretboard with the guitar's neck pointed straight up towards the ceiling.
The chord used in the chord diagram above is a C Major chord. The black circles tell you to fret the A string at the 3rd fret, the D string at the second fret, play the G string open, the B string at the first fret, and play the high E string open. Playing an open string means you pluck or strum the string without fretting or holding it down. An "X" shown on the chord diagram tells you which string(s) not to play.
A number to the side of the guitar chord diagram lets you know which fret to start the chord on.