What Is an M3U File?
A file with the M3U file extension is an Audio/video Playlist file that stands for MP3/VIDEO URL,
and as such, isn't an actual audio file in and of itself. An M3U file just points to audio/video files so that a media player can queue them for playback
These text-based files can contain URLs and/or absolute or relative pathnames to the media files and/or folders.