Another type of iPod , called the iPod shuffle , is very small , and it uses flash memory , like the iPod nano but it has no screen . The second - , third - , and fifth-generation iPod Shuffle uses a single 3.5 mm jack which acts as both a headphone jack and a data port for the dock . The dock connector also allowed the iPod to connect to accessories , which often supplement the iPod 's music , video , and photo playback .