Because MKV is a "container" that can hold multiple audio, video, and subtitle tracks, it isn't always supported natively by default system players like QuickTime or older versions of Windows Media Player.
: The most reliable and popular tool for playing MKV files on Windows, Mac, and mobile devices. 2023-01-08 14-42-35.mkv
Many professional video editors (like Adobe Premiere Pro) have historically struggled with MKV files. Because MKV is a "container" that can hold