: The .m4v extension is a video container developed by Apple. It is very similar to .mp4 but may occasionally include Apple's FairPlay DRM (Digital Rights Management) protection.
If you tell me (e.g., in a specific folder on your PC, a backup, or an app), I can help you identify what it is or how to open it. 58a3d60c-5f7c-4b46-b829-4848c6a989c6.m4v
: If you found this in a cache folder, it is likely a temporary file created during a cloud sync (like iCloud) or while downloading media in a messaging app. or an app)