Below each chord name you see a schematic overview of the neck of the guitar.
The vertical lines are the strings; from the low E on the left, to the high E on the right.
The horizontal lines are the frets.
The black dots show you where to put your fingers.
Crosses show which stringsare not played in the chord.
Open chords are played near the end of the neck, shown with a thick brown line. Other chords, so called 'bar chords', are played further up the neck, with the index finger pushing down many strings at the same time. This is shown by a black horizontal line, with the number of the fret where your index finger should be shown across it. (For instance, the 4th picture below shows an A chord, played with the index finger across the 5th string, and other fingers positioned as shown by the dots.)

A#=Bb , A#7=Bb7 , etc

Db=C# , Dbm=C#m , etc

Eb=D# , Ebm=D#m , etc