❶ Hold Switch. At the top of the Classic, over on the left side, is a little sliding switch marked Hold. This is a control that deactivates all the iPod's front buttons. Turning on the Hold switch stops your iPod from popping on if the buttons accidentally get bumped. The Nano's tiny Hold button is also on the top-left edge; the Touch doesn't have a Hold button, since it locks its screen when you press its Sleep/Wake button on top.
❷ Headphone Jack. Your new iPod comes with its own bright white headphones, and they plug in right here. If you don't like Apple's headphones, you can use another style or brand, as long as the other headphones use the standard 3.5-millimeter stereo miniplug.
❸ Dock Connector. The flat port on the iPod's bottom is called the Dock Connector. This is where you plug in the USB cable so you can connect iPod to a computer for battery-charging and music- and video-fill ups. (The Nano's headphone jack is also on the bottom.)