Triad[]
A triad is a group of 3 notes which determines the basic sound of a chord.
If a chord is a minor, it will be based on a minor triad. (The triad of a un-altered minor chord is 1-b3-5.)
If a chord is major, it will be based on a major triad. (The triad of a un-altered major chord is 1-3-5.)