Use Kindle Fire HD's Quick Settings to set up the most commonly used functionality for your device. You access the Quick Settings in the following table by swiping downward from the top of the Kindle Fire HD screen; the Quick Settings buttons are displayed along the top of the screen.

Setting Description
Unlocked This is a toggle feature, meaning that you tap it to lock your device, displaying a black screen, and then you tap the setting again to unlock it, displaying the Home screen.
Volume Tap the Volume which displays a slider bar that you can use to increase or decrease the volume. Volume settings in individual apps, such as Music, will adjust in relation to this system-wide volume setting.
Brightness Tap this button to display Automatic Brightness On/Off buttons. Use these buttons to turn on or off a feature that controls the brightness of the screen based on ambient light. You can also use the slider beneath this setting to adjust the brightness manually.
Wireless Tap to display an On/Off button that you can use to turn Wi-Fi on or to put the Kindle Fire HD in Airplane Mode. With the Airplane Mode setting on, no available networks appear or can be connected to.
Sync If you're within range of a Wi-Fi network, when you begin to download content, it downloads very quickly. However, if you've been out of range of a network, you might want to use this setting when you're back in range of a network to manually initiate the download of new content or continue downloads that may have been interrupted.
More The More button on the Quick Settings bar takes you to Help & Feedback, as well as a complete menu of settings for every aspect of Kindle Fire HD, from Sounds & Display to your account and applications settings.