In music theory, intervals are the distances between two notes. A major interval is typically larger and has a brighter sound, while a minor interval is smaller and often sounds more somber. For example, the distance between the first and third notes of a major scale forms a major third, whereas the same distance in a minor scale forms a minor third. Intervals can be measured in half steps, with major intervals usually spanning four half steps and minor intervals spanning three. Understanding these intervals is essential for musicians, as they form the basis for chords and melodies in various musical styles.