Play your channels in a local media player. This is mostly meant for testing purposes and to show what endpoints are available.
The /video endpoint is the one used by IPTV player or Plex to play the channel's content. It creates a single mpegts stream for the channel out of all of the videos scheduled for it. For this reason, it needs the videos to be formatted to the same codec and resolution (normalized). Use this endpoint to debug issues with Plex/IPTV players or when the other endpoints don't work correctly in your player.
The /m3u8 endpoint (misnomer) sends the channel as a playlist of videos, which allows some players to play the channel in sequence without the need for a single stream. Since there is no need for a single stream, it requires less normalization work .
The /radio endpoint plays only the audio of the channel, effectively turning it into a radio station. If you only need the audio, this endpoint is much more efficient as it will not need to extract or transcode video at all.