These adapters were required after Apple moved to Lightning from the old 30-pin connector which had dedicated pins for HDMI output. As the USB 2.0 link used with Lightning does not have the ...
The first is the mini-HDMI, or Type-C. This is about half the size but still has all the 19 pins, though some of them have their uses swapped. It’s seen on the side of DSLRs and mirrorless cameras.