Is your Mac up to date with the latest version of the Mac operating system? Is it using the version required by some 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.

1. Mac Os Cheetah System Requirements
2. MacOS Big Sur

1. It is a conglomoration of NeXTSTEP, A/UX, and Mac OS 9. It is based off the unix kernel and provides compatibility with X11. It features a new theme called Aqua which replaces Platinum from Mac OS 8 and 9. It also adds the Dock as a place to launch applications (Not dissimilar to the underused Launcher) as well as some other features.
2. Mac OS X Cheetah (10.0) is the first retail release of Mac OS X, which was released on 24 March 2001.
3. MacOS X was Apple's replacement for their classic MacOS.MacOS X is based on NeXTSTEP, a Unix-based OS. The first consumer release also featured a new user interface appearance called 'Aqua'.
4. Mac OS X 10.0, dubbed “Cheetah” went on sale for $129 on March 24, 2001. It brought the Aqua user interface and technology like preemptive multitasking and protected memory to a wider audience than the Public Beta. Cheetah required 128 MB of RAM, which seems meager today, but was more than most Mac users had in their systems at the time.

If your macOS isn't up to date, you may be able to update to a later version.

Mac OS X’s built-in calendar program, iCal, is now five years old, but Leopard’s iCal 3.0 is the first version that doesn’t feel like a toy. The iCal interface is more straightforward.

Which macOS version is installed?

Mac Os Cheetah System Requirements

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.

Which macOS version is the latest?

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 Big Sur