Sometimes you have only one HDMI port on your computer (typically on a laptop), but need two ports so that you can connect 2 external monitors. In this case: You can use a switch splitter or display splitter to have two HDMI ports.
Can you connect two external monitors to each other?
Its possible, at least technically, to add as many monitors as your laptop has USB ports in this fashion. For quick and cheap multiple monitor setups, its best to combine your laptops own screen, one monitor attached with HDMI/DisplayPort/DVI, and one on a USB adapter.
How do I extend two external monitors?
Windows 10Right click on an empty area of the desktop.Choose Display Settings.Scroll Down to the Multiple displays area and select select Duplicate these displays or Extend these displays.