user interface

User interface
iPods with color displays use anti-aliased graphics and text, with sliding animations. These iPods have five buttons and the later generations have the buttons integrated into the click wheel — an innovation which gives an uncluttered, minimalistic interface. The buttons are:
Menu: to traverse backwards through the menus, and toggle the backlight on older iPods
Center: to select a menu item
Play / Pause: this doubles as an off switch when held
Skip Forward / Fast Forward
Skip Backwards / Fast Reverse
Other operations such as scrolling through menu items and controlling the volume are performed by using the click wheel in a rotational manner, while an additional Hold switch helps prevent accidental button presses. iPod shuffle does not have a click wheel and instead has five buttons positioned differently to the larger models: It has a Play / Pause button in the center, surrounded by four buttons: Volume Up / Down and Skip Forward / Backwards. The later models automatically pause playback when the headphones are unplugged from the headphone jack, but playback does not resume upon re-insertion. An iPod that has crashed or frozen can be reset by switching Hold on then off, then pressing Menu and Center (Menu and Play on the third generation iPod) for 6 seconds.