There are five ways to play guitar chords:

click the buttons indicating all the 12 major chords (F,G,C,etc.), all the 12 minor chords (Fm,Gm,Cm,etc.) and all the 12 dominant seventh chords (F7,G7,C7,etc.);

press computer keyboard keys to play these major, minor and dominant seventh chords (e.g. Caps Lock plays F major, Tab plays D minor);

click each string on the fretboard to set a chord and then either strum the strings with the mouse or click STRUM or press the spacebar;

once the fretboard is set for a chord click keep chord to create a custom-made chord button, which can be clicked or triggered with a user-defined computer keyboard key;

click keyboard chord to indicate a chord on the piano keyboard and then click it once again to create a custom-made chord button.