 Until about the end of the twentieth century, prices and capacities allowed backing up a desktop hard drive to tape more cheaply and more compactly than backing up to an additional external or removable drive.Backing up to an external USB drive became cheaper, and the drive more compact, than tape for a non-networked machine used by a business or serious user.The key advantage of tape is that tape drives can exchange their magnetic media (the cartridges) frequently, while the magnetic media installed inside each hard disk is fixed and cannot be swapped.