The primary driver package for Windows is the "CDM" (Combined D2XX and VCP) . It makes the FT231X appear as a standard COM port (e.g., COM3).
The is a highly popular USB-to-serial UART (Universal Asynchronous Receiver/Transmitter) interface chip manufactured by Future Technology Devices International (FTDI). It converts USB signals to serial (RS-232) logic levels, enabling legacy hardware, microcontrollers (like Arduino), and DIY electronics to communicate with modern computers via a USB port.