M3U8 looks nearly identical to M3U at a glance, but it's specifically the UTF-8 encoded variant standardized as part of the HLS protocol.
What UTF-8 encoding means here
UTF-8 is a text encoding standard that reliably supports international characters — important for channel names in different languages and scripts. The ".m3u8" extension signals that the file follows this encoding plus the HLS-specific playlist structure.
Master vs. media playlists
HLS actually uses two levels of M3U8 file: a master playlist listing available quality levels, and media playlists listing the individual video segments for each level. See our HLS explainer for a full example.
Do I need to know the difference day to day?
Not really — your player app handles this automatically. It's useful background if you're troubleshooting or just curious what's actually happening when you load a channel.