This adapter was more than just an accessory; it represented Apple’s acknowledgment ... or the earlier transition from the 30-pin dock connector to the Lightning connector.

The 30-pin cables and docks were adapted or updated. Lightning is digital, whereas Apple's previous 30-pin interface was both analog and digital. Although adapters let 30-pin cables plug into ...

The current interface is USB Type C, which superseded Apple's own 30-pin and Lightning connectors as ... a Type C-to-3.5mm adapter is used, which contains a digital-to-analog converter.