Here's why some monitors have two USB ports (and the best ways to use them)

There's no rule that a monitor with two visible USB ports must have one upstream and one downstream port. For example, a model might have two downstream USB-A ports and a separate USB-B upstream port, ...
Ars Technica

Connecting a desktop PC to USB-C monitor with HDMI for video - will this work?

I have a Dell U2720Q monitor that accepts HDMI 2.0, DisplayPort 1.4 and USB-C. I use USB-C because the monitor acts as a hub for a range of peripherals (keyboard, mouse, webcam, speakers, etc.etc) and ...