Lesson 1: All About OS X

What is OS X?

This tutorial is no longer updated and may be out of date. We recommend using the current version, macOS Basics.

OS X (pronounced O-S ten) is an operating system designed by Apple. The operating system is what allows you to use a computer. OS X comes preloaded on all new Apple Macintosh computers (commonly known as Macs).

OS X makes it possible to complete all kinds of everyday tasks on your computer—for example, you can use OS X to browse the Internet, check your email, edit digital photos, listen to music, and play games.

screenshot of OS X

OS X is also used in some offices because it gives you access to productivity tools such as calendars, word processors, and spreadsheets.

screenshot of OS X

Earlier versions of Mac OS have been around since the mid-1980s. Apple released the first version of OS X in 2001. There have been many versions of OS X since then, but the most recent ones include High Sierra (to be released in 2017), Sierra (2016). El Capitan (2015), and Yosemite (2014).

In recent versions, Apple has rebranded OS X as macOS (for example, macOS Mojave). However, the interface is still very similar, and for most purposes the terms OS X and macOS can be used interchangeably.