Many security cameras and dashcams (such as those from G-Series manufacturers) use a "G" prefix followed by a numerical sequence to categorize recorded events or "G-sensor" triggered clips (files saved automatically during a sudden impact).

If this was found in a specific folder or thread, the surrounding files or posts usually provide the necessary context.

Look at the file's "Properties" or "Get Info" to see the "Date Created" or "Origin URL," which can pinpoint when and where it was saved.

If you have the file and are trying to identify it, you can take these steps: