A triad is the most basic type of chord and consists of three notes stacked in thirds. There are four types of triads: major, minor, diminished, and augmented. Each type has a specific interval pattern between the root, third, and fifth notes. Major triads have a major third from the root to the third and a minor third from the third to the fifth. Minor triads have a minor third from the root to the third and a major third from the third to the fifth. Diminished triads have two minor thirds. Augmented triads have two major thirds. Triads are considered the basic building blocks of music.