The is a text-based file, typically provided as a .txt or .m3u file, that contains a curated list of IPTV links.

http://example-server.com:8080/get.php?username=user&password=pass&type=m3u_plus&output=ts

An M3U (.m3u or .m3u8) file is a plain text file that contains a list of pointers to media files or live streams on the internet. Instead of containing actual video data, the file lists the web addresses (URLs) where an IPTV player can find the streams. It also contains metadata, such as the channel name, group category, and logos. A typical entry in an M3U file looks like this:

: It also provides a long URL (the M3U string) that points directly to a playlist of media resources. This file type is a simple text file that tells a media player exactly where to find video segments on the internet. Key Features of the "X118 Mix" Format

Comprehensive Guide to X118 Mix M3u Playlists and Xtream Codes