The Velocity RS232 Port Windows driver is a software package designed to enable communication between a computer and a device that uses the RS232 serial interface (also known as a COM port or serial port). "Velocity" could refer to a particular brand or model of serial communication hardware, but the name alone doesn't directly point to a specific product. RS232 ports are used for serial communication, often for connecting industrial equipment, network hardware, and other serial devices to a computer.
In this case, the driver allows your Windows computer to recognize and properly communicate with the Velocity RS232 hardware via the serial port.