What are the three most common D-Sub connectors?

1, DB9 connector:
The DB9 connector is the smallest type of D-Sub connector, with 9 pins and a D-shape. It is widely used in serial communication, such as serial communication in the RS-232 standard. DB9 connectors are commonly used to connect computers to peripheral devices such as modems, printers, and serial mice. Due to its compact design, the DB9 connector performs well in space limited applications and has become a standard feature in many traditional devices.
In some automatic control systems, DB9 connectors are also used to connect various sensors and actuators, enabling information exchange between devices. Despite being gradually replaced by USB interfaces in modern computer communication, DB9 connectors still play an important role in some special situations.
2, DB15 connector:
The DB15 connector is a medium-sized member of the D-Sub connector family, with 15 pins. It is commonly used for connecting video and gaming devices, such as VGA (Video Graphics Array) display interfaces. In past computer systems, the DB15 connector was one of the main interfaces for connecting displays to graphics cards.
In addition to its applications in the computer field, DB15 connectors are also widely used in game controllers and various industrial control systems. Due to the increase in the number of pins, DB15 connectors are more flexible and have a wider range of applications compared to DB9 connectors when transmitting more data and signals.
3, DB25 connector:
The DB25 connector is the largest type of D-Sub connector, with 25 pins. It played an important role in early computer systems, mainly used for parallel port printers and other devices that required high data transfer speeds. However, with the development of technology, more advanced interfaces such as USB have gradually replaced the DB25 connector in the field of computers.
Although the application in the computer field is gradually decreasing, DB25 connectors are still widely used in some industrial automation systems. Due to its large number of pins, the DB25 connector can transmit multiple signals simultaneously, making it excellent in situations where high-density signal transmission is required.