OS X Mountain Lion For Dummies

Gnawing to the Core of OS X

The operating system (that is, the OS in OS X) is what makes a Mac a Mac. Without it, your Mac is a pile of silicon and circuits — no smarter than a toaster.

“So what does an operating system do?” you ask. Good question. The short answer is that an operating system controls the basic and most important functions of your computer. In the case of OS X and your Mac, the operating system

Manages memory

Controls how windows, icons, and menus work

Keeps track of files

Manages networking

Does housekeeping (No kidding!)

Other forms of software, such as word processors and web browsers, rely on the operating system to create and maintain the environment in which they work their magic. When you create a memo, for example, the word processor provides the tools for you to type and format the information. In the background, the operating system is the muscle for the word processor, performing crucial functions such as the following:

Providing the mechanism for drawing ...