The most common D-SUB connector is the VGA parallel port (DB25 female) on the personal computer, the COM serial port (DE9 male) and the bridge between the graphics card and the display. It is responsible for outputting the corresponding image signal (DB15) to the display. As an industry standard connector, the d-sub connector is used in a variety of c series modules. For the most part, the difference in d-sub attachments is only the number of pins in the connector. The expansion of the d-sub series adds new economical connectors. This new series is geared toward the growing number of applications that require fewer plug-ins, such as set-top boxes, controls and meters.