Charleen, the thumbs up is like a pat on the back for the photographer "nice shot!" or "beautiful rose". Or a pat on the back for the gardener who grew it, etc.
The star is more like a bookmark for you personally. You can click a star for something you might want to find later like how to propagate from cuttings, how much to fertilize roses. It could be anything on the site you might want to reference later. Then from your profile, you can click on "starred items" and find that information.
Karen
