Remember when you could get rid of unwanted books, CDs, and DVDs by giving them away or selling them? Or if you really hated them, hurling them into a trash can? The digital age has made purging much more complicated.
You can delete an app you don't use or a song you don't like from your iDevice, but it will still be hanging around in the iCloud, wasting space, hoping you'll re-download it. Fortunately there is a way to permanently delete content through iTunes, even if it lacks the satisfaction that comes with defenestration.