If it has been deleted, the shortcut will fail to open. If the file/folder opens, you will be able to find it. You can verify that it still exists by opening the shortcut itself. The file or folder in question must still exist. If you have the shortcut to a file on your desktop, or any other place on a drive, and you need to locate the original file, it’s fairly easy to do.
Of course, shortcuts to files have other uses and you can’t pigeonhole them when it comes to how they’re used. If you ever accidentally delete the shortcut, the file itself remains untouched. To make accessing it easier, you can create a shortcut to the file and use that to open it. If you have an exceptionally important file, one that you cannot afford to lose, you should always store it somewhere you’re unlikely to delete it.