How tightly information is packed together on a storage medium (tape or disk). A higher density means that data are closer together, so the medium can hold more information. Floppy disks can be single-density, double-density, high-density, or extra-high-density. To use a double-density, high-density, or extra-high-density disk, you must have a disk drive that supports the density level. Density, therefore, can refer both to the media and the device.