For the uninitiated, refers to a single video file (typically MKV or MP4) that contains two or more separate audio tracks. In the case of Dragon Ball Super: Broly (2018) , a proper Dual Audio release includes:
It allows fans to compare cultural nuances. The Japanese track emphasizes the "martial artist" tone of Goku (childlike, serious in battle). The English track emphasizes the "superhero" tone (more booming, heroic declarations).