Direct access storage device. storage method available with disks in which data can be located by its address rather than sequentially.
Direct Access Storage Device. This is the main storage structure in Mainframe. It refers to disk systems attached to the computer via SCSI, IDE media
Direct Access Storage Device. A long established IBM term, which currently means a disk device; historically there were other kinds of direct access storage (e.g. magnetic cards) which may explain the rather generic terminology.