Guitar chords are combinations of notes played together on a guitar. Each chord is formed by pressing down specific strings on the fretboard, creating a harmonious sound. Chords are typically named after their root note, such as C major or G minor, and can be played in various positions and shapes. There are two main types of chords: major and minor. Major chords sound bright and happy, while minor chords have a darker, more somber tone. Learning basic chords is essential for playing songs and allows guitarists to express a wide range of emotions through music.