The iPod nano is Apple's fourth digital audio player combining features of both the iPod shuffle and iPod. It was introduced on September 7, 2005, replacing the iPod mini, which was discontinued on the same day. The replacement of the mini took Apple-related websites and the press completely by surprise since, although there were rumors about a new flash memory-based iPod, there was no prior notice of the popular mini being discontinued.

Work on development of the new design of the iPod nano started only nine months before the launch date. The iPod nano has more flash memory storage than is used in the iPod shuffle and has a miniaturized version of the color screen and click wheel found on the full-sized iPods. The screen also has a higher resolution than the old grayscale iPod, allowing one more line of text than the mini's screen. The battery and other internal parts were also reduced in size. The surface of the click wheel is slightly textured, allowing greater tactile feedback for out-of-sight operation. Also, the center button on the second-generation iPod nano is slightly concave, most likely so that it would be easier to find without looking. Unlike other players in the iPod family, the iPod nano has a headphone-out situated in the bottom right of the player.