What is the Operating System?

Posted By BrokenClaw on November 2, 2007

The operating system, abbreviated OS, is the foundation layer of software that makes it possible for the computer to run other programs, also called applications. When you turn on a computer, the first thing that runs is the BIOS, the Basic Input/Output System. The BIOS is what checks connections to the hardware, such as the keyboard, hard drives, and optical drives. The BIOS then looks for an operating system to start up. With just a BIOS, a computer can be alive, but it needs an operating system to be awake.

The process of starting the operating system is called booting, or booting up. The term boot and reboot are also used as verbs in phrases like boot the computer, reboot the computer, a hard reboot (turning it off and then on), a soft reboot (telling the computer to reboot itself), and the always dreaded, my computer won’t boot!

The operating system controls all aspects of the computer. To the user, it’s what pops up on the screen when you turn it on. The main screen is called the desktop, where the user interacts with the computer by clicking on icons. That system of icons is called a graphical user interface (abbreviated GUI, and sometimes pronounced goo-ey). Before the GUI became the norm, computer users typed all the commands on a blank screen.

The operating system manages user input from the keyboard and mouse. It allocates system resources to run programs, manage memory, and control the disk drives. It controls the output to the monitor, speakers, and printers. It handles the network connections and directs the file system. The operating system must be functional before any other programs can be installed.

The operating system includes a bunch of processes that run in the background and only become apparent when they don’t work. One of those things is called a driver. A driver is really just a set of instructions that tells the computer how to make a peripheral device work. For example, every printer needs its own driver so that the computer can control exactly how the dots are printed on the paper. In fact, whenever you add a new peripheral device, the process includes the installation of a new driver.

An operating system is required of all digital devices, not just computers. Every cell phone, PDA, gaming console, DVD player, and digital video recorder has some type of operating system.

Read more about Varieties of Operating Systems.


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