D-Sub, short for D-subminiature, is a type of electrical connector commonly used for video and data transmission. It features a distinctive D-shaped metal shell that provides a secure connection and helps prevent incorrect insertion. D-Sub connectors come in various sizes and pin configurations, making them versatile for different applications, including computer monitors and serial communication. These connectors are often found in devices like computers, projectors, and televisions. The most well-known variant is the VGA connector, which is used for video output. D-Sub connectors are reliable and have been a standard in the industry for many years, despite the rise of newer technologies.