DB-xx is the designation for a series of port connectors for attaching devices to computers. DB-xx connectors include DB-9, DB-15, DB-25, DB-50, and DB-68.
DB-9 is a connector used for RS-232 connections and for several video interfaces on IBM-compatible computers.
DB-15 is a female connector used as a joystick port on IBM-compatible computers and as the video connector on Macintosh computers. There is also a high-density DB-15 female connector for the Video Graphics Array (VGA) or Super Video Graphics Array (SVGA) video adapter on IBM-compatible computers.
DB-25 is a male connector used for attaching external modems and RS-232 serial peripherals on older IBM-compatible computers. The DB-25 female connector is the parallel port connector for most personal computers. DB-25 was first used with the original IBM personal computer (PC) and has had a long life.
DB-50 is a female connector used as the SCSI-2 connector for 8-bit Narrow SCSI devices on older Sun and Data General computers. However, DB-50 is not recognized by the SCSI specifications.
DB-68 is a high-density connector used as a SCSI-3 connector for 16-bit Wide SCSI and Fast SCSI devices.