This device appears to contain its own graphics card. This means, if you’re using a laptop, that it will allow you to run three monitors (the laptop one itself and two external monitors) with each monitor displaying a different image / software to the others. Or you can set them to all show the same image, but I’m not sure why anyone would want to.
https://www.amazon.com/USB-Dual-HDMI-Adapter-External/dp/B0725K1MHH

