Common questions about your Mac
How do I get support for my MacBook Air? Go to MacBook Air Support.
I’m new to Mac. Are there tips for PC users? Yes! See Are you new to Mac? and the Apple Support article Mac tips for Windows switchers.
How do I take a screenshot on my Mac? Press Command-Shift-3 to take a screenshot of the entire screen. Press Command-Shift-4 to take a screenshot of a selected area of the screen. To learn more, see Take a screenshot on your Mac.
Where is my serial number? Choose Apple menu 
> About This Mac. The serial number is the last item in the list. You can also find the serial number on the bottom of your MacBook Air.
How do I know which model of MacBook Air I have? See the Apple Support article Identify your MacBook Air model. You can also choose Apple menu > About This Mac to view the model information.
How can I find the documentation for my MacBook Air? To find the MacBook Air Essentials guide, choose Apple menu > About This Mac, click the Support tab, then click User Manual. From the Support tab, you can also click “macOS Help” to open the user guide for the operating system. For older Mac models, see Browse manuals by product.
How do I get help for an app? When you’re using the app, click the Help menu in the menu bar at the top of the screen.
Where is the safety information for my MacBook Air? See Important safety information for your Mac.
How do I find the technical specifications? Go to MacBook Air Tech Specs, or choose Apple menu > About This Mac, click Resources, then click Specifications.
How do I check my disk for problems? Use Disk Utility. See Repair a storage device in Disk Utility on Mac in the Disk Utility User Guide.
How do I reinstall macOS? Use macOS Recovery. See How to reinstall macOS from macOS Recovery.
Note: Beginning with macOS Big Sur, Time Machine backups don’t include system files. See Back up and restore your Mac.
What should I do before selling or trading in my Mac? Back up your data, then restore your Mac to factory settings. See What to do before you sell, give away, or trade in your Mac.