CertiGuide to A+ (Operating Systems)  9  Chapter 0000:  How to Get There       9  II  How Operating Systems Work

Anatomy of an OS 1 Operating Systems for the A+ Certification Test

An Operating System (OS) is a collection of special programs running on your computer, which sits between the computer hardware, which you learned about in A+ Core, and application (task-oriented) programs such as word processors, Internet browsers, email programs and spreadsheets.

The Operating System is the set of utility functions and programs that make it possible for applications to access your computer hardware, and for you to manage the use of your applications and the hardware.

Because it must perform many hardware-specific functions, an Operating System is specific to the type of computer on which it will be run.

For example, there are Operating Systems which run on standard PC's, with Intel or AMD processors, and motherboards with PCI or ISA slots.

There are also Operating Systems for Macintosh computers, and other Operating Systems for larger mini-computers and mainframes.

Some Operating Systems like Linux are available for multiple different types of computers. However, it is more common for an Operating System to be associated with a certain type of computer. For example, Intel and AMD CPU-based PC's generally run some version of Windows.

Anatomy of an OS 1 Operating Systems for the A+ Certification Test