Apple updates its macOS desktop and laptop operating system once a year, like clockwork, bringing new features and improvements. That’s all very well, but Apple’s most recent version of macOS, Sequoia, won’t run on a MacBook Air from before 2020, a Mac mini or MacBook Pro that launched before 2018, iMac’s from before 2019, or the Mac Pro from before 2019. If your Mac is too old to be supported you are out of luck… Or are you?
What if your Mac or MacBook is older than those mentioned above? Officially this means that your Mac can’t officially be updated to macOS Sequoia. Unofficially, though, it can be done. If Apple deems your Mac too old to run Sequoia, or any other versions of macOS, updating is not simple, but it is possible with an OpenCore Legacy Patcher.
Read more at Macworld.com