Lightning is one end of the cable, with USB Type A at the other. Introduced in 2012 with the iPhone 5 and new iPods, Lightning superseded the 30-pin dock connector that dates back to 2001.

In 2012, we said goodbye to 30-pin, and Lightning became Apple's main connector. But, seven years later, it's on only two types of devices: iPhones and lower-end iPads. When Apple introduced the ...