Add comments to photographs

Hello i'm using Aeon Nox (not sure whether this is skin related), I would like to add comments to my photographs, do I have to create some sort of nfo file? or can I embed the comment in the metdata of the picture itself (I've had a look at the metadata of my photos and haven't found a tag for comment (everything else is there ,camera, location, GPS) can anyone help me also if its easy can I create a comment for a folder of pictures?