The Application3 Port is not a specific, widely-recognized device like a network adapter or USB device, but rather likely refers to a serial port or communication port (e.g., COM port) associated with certain hardware or software applications. The term "Application3 Port" might appear in Device Manager or in connection with specific hardware that needs to interact with the computer via a serial or virtual port.

In general, serial ports (often labeled as COM ports in Windows) are used for communication between the computer and external devices, such as printers, scanners, modems, and other peripherals. The Application3 Port could be a generic name for one such port, and the driver required would likely be for the hardware or software that is using this port for communication.