USB graphics adapters let you easily add an additional monitor to your PC or Mac. You can use any existing monitor, connect it to your USB graphics adapter, install DisplayLink software, and plug it into any USB port. There's no easier way to add an additional monitor to your PC or Mac. You can add up to six additional monitors to your PC or four additional monitors to your Mac, Chromebook or Ubuntu installation - you just need one USB graphics adapter for each monitor you want to add.

https://www.displaylink.com/products/usb-adapters