The first release of the new OS — Mac OS X Server 1.0 — used a modified version of the Mac OS GUI, but all client versions starting with Mac OS X Developer Preview 3 used a new theme known as Aqua. Aqua was a substantial departure from the Mac OS 9 interface, which had evolved with little change from that of the original Macintosh operating. All versions of Mac OS X that were made to run on PowerPC systems (with the exception of Leopard) had a Mac OS 9 emulation layer called 'Classic'. It allowed Mac OS X to run Mac OS 9 applications that weren't updated to run natively on OS X (known as carbonization based on the Carbon API). Mac OS X 10.0 was a radical departure from the classic Mac OS and was Apple's long-awaited answer for a next generation Macintosh operating system.
Is your Mac up to date with the latest version of the Mac operating system? Is it using the version required by a product that you want to use with your Mac? Which versions are earlier (older) or later (newer, more recent)? To find out, learn which version is installed now.
If your macOS isn't up to date, you may be able to update to a later version.
From the Apple menu in the corner of your screen, choose About This Mac. You should see the macOS name, such as 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.
These are all Mac operating systems, starting with the most recent. When a major new macOS is released, it gets a new name, such as macOS Big Sur. As updates that change the macOS version number become available, this article is updated to show the latest version of that macOS.
If your Mac is using an earlier version of any Mac operating system, you should install the latest Apple software updates, which can include important security updates and updates for the apps that are installed by macOS, such as Safari, Books, Messages, Mail, Music, Calendar, and Photos.
macOS | Latest version |
---|---|
macOS Big Sur | 11.3 |
macOS Catalina | 10.15.7 |
macOS Mojave | 10.14.6 |
macOS High Sierra | 10.13.6 |
macOS Sierra | 10.12.6 |
OS X El Capitan | 10.11.6 |
OS X Yosemite | 10.10.5 |
OS X Mavericks | 10.9.5 |
OS X Mountain Lion | 10.8.5 |
OS X Lion | 10.7.5 |
Mac OS X Snow Leopard | 10.6.8 |
Mac OS X Leopard | 10.5.8 |
Mac OS X Tiger | 10.4.11 |
Mac OS X Panther | 10.3.9 |
Mac OS X Jaguar | 10.2.8 |
Mac OS X Puma | 10.1.5 |
Mac OS X Cheetah | 10.0.4 |