For example, if it says you have macOS Mojave version “10.14.1” installed, this means you have Mojave with the “.1” update installed.
In the screenshot below, we have version 10.14 of macOS Mojave installed. As long as it starts with “11.”, you have Big Sur installed. If you see “macOS Big Sur” and version “11.0”, you have Big Sur. The name and version number of your Mac’s operating system appears on the “Overview” tab in the About This Mac window.
