The GPS USB Serial Interface Driver is a software driver that allows a GPS device (which communicates over a USB port) to interface with a Windows computer through a serial (COM) port. Many GPS receivers or modules connect to a computer via USB and emulate a serial connection, meaning the GPS data (such as location, speed, and coordinates) can be read by software that communicates with the serial port.

The driver essentially enables your computer to "talk" to the GPS device by assigning it a virtual serial COM port through which GPS data can be transmitted. Once installed, GPS-enabled software (such as navigation software, mapping tools, or even custom applications) can access the GPS data via the COM port.