Difference between "remove selected item" and "delete from library"?

Sorry that this may be a stupid question, but I can't quite find a definitive answer. What's the difference between choosing (when you right-click on an item) "remove selected item" and "delete selected item from library"? I'm afraid that deleting it will delete ALL instances of it, whereas what I want to do is simply delete duplicate instances of it. Should I use "remove"? Thanks!
Sign In or Register to comment.