Know your Mac’s serial number will help you to identify your system with Apple. There’s an online official Apple serial number checker here: https://selfsolve.apple.com/GetWarranty.do?newid=y which allows you to enter your Apple’s serial number and get a lot of information related to your device.
There are a lot of ways to check your Mac serial number, one of the method I normally use is using Terminal, which is consistent across various versions of Mac OS, and in this article, I will show you how to do that:
1. Open Terminal (from Spotlight or Application\Utilities folder)
2. Enter the command
system_profiler | grep "r (system)"
3. Wait a little, and the system will reply you with the serial number of your Mac:
Serial Number (system): <Your serial number here>

