MacBook Air Keyboard
The function keys on the keyboard provide shortcuts for common functions, such as increasing the volume or screen brightness.
Touch ID (power button): Press to turn on your MacBook Air (or just lift the lid or press any key). When you first start up or restart, you need to log in by typing your password. You can set up Touch ID during setup or later in the Touch ID pane of System Preferences. After setup, whenever you’re asked for your password after you first log in, you can place your finger lightly on the Touch ID sensor to authenticate instead of typing your password.
You can also use Touch ID to make purchases online securely with Apple Pay. For more information about Touch ID, see Set up your Mac. For more information about Apple Pay, see Use Apple Pay on your Mac.
Note: To turn off your MacBook Air, choose Apple menu 
> Shut Down. To put your MacBook Air to sleep, choose Apple menu > Sleep.
Brightness keys (F1, F2): Press
or 
to decrease or increase the brightness of the screen.Mission Control key (F3): Press
to view what’s running on your MacBook Air, including all your spaces and open windows.Launchpad key (F4): Press
to instantly see all the apps on your MacBook Air. Click an app to open it.Keyboard illumination keys (F5, F6): Press
or 
to decrease or increase the brightness of the keyboard.Media keys (F7, F8, F9): Press
to rewind, 
to play or pause, or 
to fast-forward a song, movie, or slideshow.Mute key (F10): Press
to mute the sound from the built-in speakers or 3.5 mm headphone jack.Volume keys (F11, F12): Press
or 
to decrease or increase the volume of sound from the built-in speakers or 3.5 mm headphone jack.Function (Fn) key: Each function key (on the top row) can also perform other functions—for example, the F12 key can open Dashboard. Hold down the Fn key while you press a function key to trigger the action associated with the key.
Tip: Press the Fn key twice to turn on dictation, which lets you dictate text wherever you can type it (for example, in Messages, Mail, Pages, and many other apps).
Set keyboard preferences. Use the Keyboard pane of System Preferences (choose Apple menu > System Preferences, click Keyboard, then click the buttons at the top to see the available options).
Learn about keyboard shortcuts. You can press key combinations to do things on your MacBook Air that you’d normally do with a trackpad, mouse, or other device. For a list of commonly used shortcuts, see Keyboard shortcuts on your Mac.