ELI5: Explain Like I'm 5

M3U

An m3u file is like a book that tells a computer what songs to play. It's a list of all the songs and music you want to listen to. It's like if you want to make your own radio station or a playlist of your favorite songs. Your computer can't play songs on its own, so it needs the m3u file to know which songs to play and what order to play them in.