A diminished chord (denoted as "dim") is a type of chord that creates a tense and unresolved sound due to its structure. This chord is built by stacking minor thirds on top of each other. For example, in a C diminished chord, the notes would be C, E♭, and G♭. Due to its symmetrical nature, the diminished chord is often used in music to create a sense of instability or to transition between more stable chords. It's prevalent in genres like jazz, classical, and some types of rock. When playing diminished chords on guitar, it’s essential to pay attention to finger positioning and fret accuracy to ensure the tension and texture of the sound are fully realized. Diminished chords can also be presented in seventh form, where a double-flatted seventh note is added, giving another layer of dissonance. They are fundamental in adding color and drama to musical compositions.