Do you remember or what the video was about ? Knowing the context could help me write a more detailed article for you.

When you receive a video on Messenger and save it to your device, Facebook's system assigns a unique numerical identifier to the file. This helps their servers track the content while keeping the original file name (like "MyDog.mp4") private or standardized within their database.

: "received" indicates the file was sent to you by another user.