When a video is "cached" to load faster for you, it is often stripped of its descriptive name (e.g., "vlog_final_v2.mp4") and assigned a cold, efficient number.
Platforms like Pexels, Shutterstock, or Pixabay assign these IDs to track downloads and licensing. 12897710-720p.mp4
You will typically encounter this naming convention in three specific environments: When a video is "cached" to load faster