M3U8: The Buffet-Style Format
M3U8 chops video into small pieces you grab as needed. Pros: fast loading, quality switching, great for live streams. Cons: needs a stable connection and more files to manage.
MP4: The Whole Steak
MP4 is a single complete file. It's perfect for local playback, downloads, and editing. Every player knows it. But large MP4s buffer online and can't switch quality on the fly like M3U8.
Which One?
Streaming, live broadcasts, multi-device delivery? Go M3U8. Local viewing, editing, offline watching? Go MP4. They're teammates, not rivals.