Want to save that article you found so that you can come back to it? Did you find a great book and want to save the link so you can pick it up later? Be sure to use a permalink or stable URL. Just copying and pasting from the address bar of your browser will not allow you to get back to your item again, unfortunately. (Sorry - it's an annoying thing with library sources.)
If you are unsure whether you have found a permalink, always note the title, author, journal title (if applicable), date of publication, and where you found the source so that you can ask a librarian for help. With those pieces of information, a librarian can usually find the article again with you.