The CH340 USB to UART is built-in to the Vanguard board, and allows your laptop to send and receive text over a USB cable.
If you are using Windows 10 or Linux, drivers are built-in, so this step is already completed.
For users of Mac OS X or Windows 7 and earlier, drivers are available here. Once you have installed the CH340 drivers, please restart your laptop.
If you have a CH340 driver, continue to the next step in connecting to the Vanguard shell over USB