A "Dual Audio" file contains two separate, selectable audio tracks embedded within a single video container (usually an MKV file).
In the scene, a “Repack” usually corrects a mistake in a previous release. The original 2011 BluRay rip had two problems:
720p video requires less processing power to decode, ensuring stutter-free playback on older computers, budget smartphones, or basic streaming sticks. The Power of Dual Audio