: By default, Windows often hides "known file extensions." A file named What The F!!!.mkv.mp4 might appear to a user simply as What The F!!!.mkv .
Double extensions are a classic trick used to hide a file's true nature. What The F!!!.mkv.mp4
It is very common for users or automated tools to rename a file rather than properly converting it. : By default, Windows often hides "known file extensions
In video editing and recording communities (like those using OBS Studio ), creators often record in because it is "crash-proof"—if your computer dies, the recording is saved up to that moment. : By default
Creators then "remux" (wrap) that MKV data into an container for easier editing in software like Adobe Premiere or DaVinci Resolve.