Besides DisplayPort over USB-C that people have already mentioned there's also eDP which is basically the standard for connecting a laptop's screen to its GPU.

Besides DisplayPort over USB-C that people have already mentioned there's also eDP which is basically the standard for connecting a laptop's screen to its GPU. You buy a laptop, regardless of what external port it has, DisplayPort is used on the internal display. And since most laptop users don't regularly connect to external displays, one can certainly say that the usage of DisplayPort here far eclipses HDMI.