M3U stands for MP3 URL. It is a format mostly associated with audio playlists but has expanded to contain visual information and can be used for multimedia files. Multimedia players use M3U files to queue files for playback. It is one of the most widely-used formats on MP3 players for audio compilations and for live streaming, which is very popular in the IPTV industry.
Many apps support M3U link such as IPTVSmarter Pro, Kodi, Roku and M3U link can be opened with VLC player on Windows PC.