Remember 30-pin? Now we have Lightning. Remember USB-A? That's gone ... If you want to connect any of Apple's laptops to an HDMI monitor, you need to spend $50 on an adapter, and dongles like ...
The current interface is USB Type C, which superseded Apple's own 30-pin and Lightning connectors ... a Type C-to-3.5mm adapter is used, which contains a digital-to-analog converter.