: Simply double-click it to open in QuickTime or Photos .
: Use VLC Media Player or the default Photos app. If it won't play, you may need the "HEVC Video Extensions" from the Microsoft Store. trim.D79F97BA-9376-4B3E-B0B1-E2B52AFE15B3.MOV
: You can save it to your Camera Roll; it will be recognized natively by any smartphone. Why do I have this? : Simply double-click it to open in QuickTime or Photos
: If someone sent you a video they just edited on their phone, this is the default name it carries. trim.D79F97BA-9376-4B3E-B0B1-E2B52AFE15B3.MOV