If you have encountered this specific filename, it is important to consider the of "source" files:

You can use standard players like Windows Media Player or VLC.

MP4 is a "container" format. It doesn't just hold video; it bundles audio, subtitles, and metadata (like timestamps or GPS data) into one package.

Using a "source" file for commercial purposes usually requires a specific license or permission from the original creator.

Because it is an international standard, a file like 0gxvoihlsjhjlgr7da1uu_source.mp4 can be played on virtually any device, from smartphones and TVs to gaming consoles . ⚖️ Digital Rights and Usage

This indicates the original, uncompressed, or master file uploaded to a server. Most platforms (like YouTube or Vimeo) take this "source" file and create multiple smaller versions (transcodes) at different resolutions (360p, 720p, 1080p) for users to stream.