How do I know which OS version I am using on the Apple Mac?

Whether you are working on a Mac desktop or a Macbook Pro (like me), you can get the information on the operating system – the version as well as the serial number and hardware details in just one click.

The thing is, when I bought the Mac I knew it had the OS X Yosemite operating system. But since I had been a Windows user all my life, I needed to understand out how one can find the operating system information on the Mac.

It’s always good to know which operating system your computer is running. Here is how you find it out on the Mac:

1. Go to the Apple menu (click that small Apple logo located at the top-right corner) [Slide 1].
2. Choose “About This Mac” from the drop down [Slide 2].
3. A small window pops up displaying the operating system information along with details of the processor, the memory (RAM), graphics card and the serial number [Slide 3].
4. You can also check out the usage of the local drive by clicking “Storage” tab [Slide 4].

From time to time, Apple will release new versions of the operating system. These may contain bug fixes to the OS itself or updates to important programs such as iTune or the App Store. I’ve noticed that a few times, these upgrades may be small (just a few megabytes) or run in hundreds of MBs.

Though it is always recommended that you have the latest version of the operating system because it would typically patch to security holes, make sure you take a backup of the important files on your computer.

Update (October 2015): I now run the OS X El Capitan operating system on my Mac.