Find out which macOS your Mac is using
Use About This Mac to check the version of Mac operating system installed, and find out whether it's the latest (newest, most recent) version.
Which macOS version is installed?
From the Apple menu in the corner of your screen, choose About This Mac. You should see the macOS name, such as macOS Monterey or macOS Big Sur, followed by its version number. If you need to know the build number as well, click the version number to see it.
