Advanced Audio Coding is a high-efficiency format that provides better sound quality than MP3 at similar bitrates.
Use a versatile player like VLC Media Player or MPC-HC , which handle MKV containers and AAC audio natively.
The Matroska Video (MKV) container is used, which can bundle multiple audio and subtitle tracks into one file.
This is standard definition, suitable for viewing on smaller screens or mobile devices without consuming high bandwidth.
If subtitles are included, they are often "soft" (selectable) rather than burned into the video, allowing you to toggle them on or off.