Common questions about your Mac
How do I get support for my iMac? Go to iMac 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. You might also be interested in Keyboard shortcuts on your Mac.
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 
How do I know which model of iMac I have? See the Apple Support article Identify your iMac model. You can also choose Apple menu
How can I find the documentation for my iMac? To find the iMac Getting Started Guide guide, open System Settings, click the Help menu, then click User Manual. From the Help menu, 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 iMac? See Important safety information for your Mac.
How do I find the technical specifications? Go to iMac Tech Specs, or open System Settings, click Help, then click iMac Specifications.
How do I hang my iMac on a wall? Use a VESA Mount Adapter. The VESA Mount Adapter should only be installed or uninstalled by Apple. For support, contact an Apple Retail Store or Apple Authorized Service Provider. For information about service, go to support.apple.com/mac/repair/service.
How do I check my disk for problems? Use Disk Utility. See Repair a storage device in Disk Utility on Mac.
How do I reinstall macOS? Use macOS Recovery. See the Apple Support article How to reinstall macOS.
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.