How do I tag pictures located in an external hard drive?
I have a million pictures located in a 2T external hard drive. They are sorted by date and location. I want to tag them so I can use them on a website, but can't find a way to do it. I don't want to transfer them to my laptop hard drive. Right now I can see them and copy them, but I want to tag them for easy retrieval. Can anyone help?
Mac Pro, OS X El Capitan (10.11.3)