How to export photos from the Photos on my mac mini into a Excire app?

In Photos, you use the menu choice File>Export>Export Unmodified Originals. The export dialog will give a choice or two and, when you OK that, there will appear another window that asks where you'd like them to go. You can create a new folder on your external drive from there, if you'd like. The result will be files indistinguishable from the original files that went to Photos.

If you've done extensive editing, then you can use File>Export>Export nn Photos to export the edited versions in a similar way.

All your pictures will still be in your Photos Library in the Pictures folder. You ought to copy that to your external drive as a backup.

I'm curious what this Excire app does that Photos doesn't-- what's it do?

You can go to the Library and do command-a to select all, and then do Export.

For originals it could be relatively quick--I haven't exported thousands of pictures, so I'm not sure. But originals

just have to be duplicated, so it's quick. Edited versions have to have their edits applied before exporting, so it takes awhile. However, if you are using iCloud, and you have checked "Optimize Storage" in the settings, then Photos may have to download full sized files from iCloud before exporting, so that could take a bit longer.

From what I saw on the web, Excire may do more. But everything you mentioned is done by Photos. Photos, for instance, doesn't rate your pictures for you-- but I might be hesitant to let the computer program decide for me which of my pictures have "aesthetic potential," even for $189!

Just like everywhere else in the OS: command-a selects all.

Say what now?

New to Mac’

The command-a shortcut works on Macs.

Not IOS as I have iPhone amd iPad

iOS is the operating system on iPhones and iPads. So frankly, I've no idea what you're saying here. Can you clarify?