Hi Ratboy, thanks for your question. I'm Graeme, a Microsoft Community expert and fellow user.
There should be a Favorites album in the Photos app which contains all the photos you've marked as favorite. The purpose is to allow quick access to your favorite photos.
Here's an article that might help you use the feature:
https://www.tenforums.com/tutorials/116097-add-...
Let me know if you're having trouble finding the favorites album!
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