What is the difference between a dominant 7th chord and a major 7th chord in music theory?

The difference between a dominant 7th chord and a major 7th chord is the type of 7th interval used. In a dominant 7th chord, the 7th interval is a minor 7th above the root note, while in a major 7th chord, the 7th interval is a major 7th above the root note. This difference gives each chord a distinct sound and function in music.