AirPods 1 and 2 are USB-A charging ports, which are the most commonly used USB charging ports. AirPods 3 and AirPods Pro are USB-C charging ports, which are the Type C ports. Relatively speaking, the charging speed of the USB-C port will be faster than that of the USB-A port. And, in the future is definitely the world of USB-C! Now the basic interface (whether it is a phone or a tablet) is USB-C.