Export video or unmodified original video?

Have you edited the video? If so:

Unmodified Original is exactly that - the video as it was imported to Photos.

If you have edited the video then the other export options yields the edited version and allows you to say the quality.

If you haven't edited the video you can still export at a different quality.

So, at heart, if you want the video as imported, use Export Unmodified Original. If you want the edited version (should there be edits) and/or if you want to change the quality of the video, then use the other option.

Also, the "edited" version includes comments you may have made in the Captions section, Keywords you might have added, a Title, changed dates or locations, and anything you've done since you took the video. As Yer_Man said, "Unmodified Original" is exactly that," and has none of those things.

"Export Unmodified Original" exports original imported image/movie as it was imported to Photos.

If you have done any metadata edits (date, location, title, caption, faces) you can export also that info in a .xmp sidecar text file (an example at the end of this post):

Then you can use 3rd party tools like GraphicConverter (screenshot below) or exiftool to merge that .xmp metadata to the original image/movie so no re-encoding is needed and there is no generation loss pixel wise.

That embedded metadata to images/movies then handily travels with them and also Photos can re-import and display it.

BUT notice that currently (in at least Sequoia and in many earlier macOS) Photos has an old issue <cough, bug, cough> so it does not properly or at all import .xmp and, worse, it silently fails to import movie if there is a movie .xmp sidecar in the import folder. So use GC or exiftool instead (they have a workaround that fixes Photos non-standard .xmp GPS which might put western and southern locations to the other side of the globe).

<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 6.0.0">
   <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
      <rdf:Description rdf:about=""
            xmlns:exif="http://ns.adobe.com/exif/1.0/"
            xmlns:dc="http://purl.org/dc/elements/1.1/"
            xmlns:photoshop="http://ns.adobe.com/photoshop/1.0/">
         <exif:GPSLongitude>74.007204999999999</exif:GPSLongitude>
         <exif:GPSLongitudeRef>W</exif:GPSLongitudeRef>
         <exif:GPSHPositioningError>1</exif:GPSHPositioningError>
         <exif:GPSLatitude>40.712982199999999</exif:GPSLatitude>
         <exif:GPSLatitudeRef>N</exif:GPSLatitudeRef>
         <exif:GPSTimeStamp>2025-12-17T16:28:27Z</exif:GPSTimeStamp>
         <dc:title>Title</dc:title>
         <dc:description>Caption</dc:description>
         <dc:subject>
            <rdf:Seq>
               <rdf:li>Keyword 1</rdf:li>
               <rdf:li>Keyword 2</rdf:li>
               <rdf:li>Face 1</rdf:li>
               <rdf:li>Face 2</rdf:li>
            </rdf:Seq>
         </dc:subject>
         <photoshop:DateCreated>2025-06-01T12:00:00+03:00</photoshop:DateCreated>
      </rdf:Description>
   </rdf:RDF>
</x:xmpmeta>