Search for the exact phrase "Ajb (202)" (with quotes) on the specific site where you found it.
Right-click the file (if you have it) and select Properties (Windows) or Get Info (Mac). Check the "Details" or "More Info" tab for a contributing artist, title, or description.
Do you know the of the video or where it was originally hosted?
Sometimes "AJB" refers to specific journals (like the American Journal of Botany ) or legal identifiers, though it's rare for these to be distributed as MP4s without further context.
It may be a specific part of a larger video collection or a re-uploaded file (where "202" indicates a part number or a copy).
Internal training videos sometimes use these codes. How to Find Your Specific Video