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, ...
DisplayPort is usually considered better, associated with high-end displays, whereas HDMI is a great affordable option that ...
Technology has come a long way since the days of CRT monitors and small screens. Nowadays, people can (and often do) set up multi-monitor workstations to improve their productivity or to have fun.
If both devices have HDMI or DisplayPort ports, then use either an HDMI-to-HDMI cable or a DisplayPort-to-DisplayPort cable to connect them. At times, when you try to connect two Lenovo ThinkVision ...