The HDMI interface is electrically identical and compatible with the video-only DVI interface, which came first. For example, if a cable box or PC has DVI out, but the TV or monitor only has HDMI ...

If your computer can handle multiple monitors or not, depends on the kind of port you have. There are multiple monitor ports available, such as VGA, DVI, HDMI, USB C, etc and you need to make sure ...