Operating System (OS)

We can define an Operating System, or simply OS, as a software program that serves as the interface between other applications and the hardware on a computer or mobile device.

Desktop operating systems perform basic tasks, such as recognizing input from a keyboard, sending output to a display screen, managing files and directories on a storage drive, and controlling peripheral devices like printers.

Operating System (What is it?)

What is the Operating System?

The operating system (OS) is the underlying software that integrates the hardware with software applications. It is distinguished from the essential hardware components in that it consists entirely of software – millions of lines of machine commands that are understood and obeyed by the microprocessor.

The Operating System actually consists of hundreds or thousands of individual programs that bundled together. Many of these individual programs are designed to work cooperatively with each other. The OS is automatically executed each time the computer is started and it is the most important software component running on any computer. A modern computer cannot operate without an OS.

Although the CPU is frequently personified as the “brain”’ of the computer, it is really the Operating System software and the CPU acting together that provides the underlying ‘‘intelligence’’ of system. The OS and the CPU are inexorably linked; therefore, the distinction between the software and the hardware is sometimes blurred.

Operating System main tasks

The OS is designed to automatically manage nearly every task (or process) including maintenance of the files on the disk, tracking input from peripheral devices like keyboards or network cards, displaying output on printers and video displays and control of memory allocation. Memory allocation is crucial for maintaining stability of the system because if two programs try to use the same area of memory, both programs will usually fail. Two of the most critical jobs of the OS are ensuring that programs do not unintentionally interfere with each other and maintaining security.

A function paramount to the modern OS is the support of the graphical user interface (GUI). A GUI replaces typed computer commands with a graphical representation of the task (e.g., moving a file). This is accomplished by creating a visual representation of the computer file system (the desktop), icons, and windows and linking them to the movements of a pointing device such as a mouse.

The Operating System also provides a foundation or software platform for all other software (application programs). Therefore, the choice of OS, to a large extent, determines which application software can be used on a particular system.

Common operating systems

Common operating systems for desktop computers are Windows, macOS, and Linux. For mobile devices: Android and iOS are the most popular operating systems.


An Operating System may consist of hundreds (or even thousands) of small programs called drivers. Drivers enable software to interact with the ubiquitous hardware devices attached to the motherboard and between components on the motherboard itself. In other instances, drivers allow one software component to safely interact with another piece of software.

Operating System from the user perspective

In conclusion, from the user perspective, the Operating System provides the framework that application software runs inside of. All application software runs on top of the OS that, in turn, is directly integrated to the hardware. In general, application software cannot interact directly with the hardware; it must work through the Operating System.

Today’s phones are also computers

Your smartphone is a computer, your smart TV is a computer, your game console, smart watches, even the latest home appliances are computers running an operating system.

Familiar desktop operating systems include Microsoft Windows, Apple macOS, Google’s Chrome OS, and Linux. The dominant smartphone operating systems are Apple’s iOS and Google’s Android.

Other devices, such as your Wi-Fi router, or GPS navigators may run “embedded operating systems.” These are specialized operating systems with fewer functions than a typical operating system, designed for more specific functions.

Is BIOS part of the Operating System?

If we accept the definition that Operating System is a piece of software designed to control the hardware of a specific equipment, we have to answer YES to that question. But I assure you that any answer would be controversial.

Basic input/output system (BIOS)

Basic input/output system (BIOS). BIOS is comprised of a non-erasable read only memory (ROM) chip that contains the minimal amount of software necessary to instruct the computer how to access the keyboard, mouse, display, disk drives, and communications ports.

When the power is first applied to the computer, the motherboard relies on the BIOS to tell what additional components are available to the motherboard for input and output (e.g., disk drives, memory, keyboard, etc.). The motherboard ‘‘becomes aware’’ of what is available and how to access it, each and every time the computer is restarted.

The BIOS also provides information to the motherboard on where to find the first piece of software to load during the startup process. The startup process is also known as the boot process. The first piece of software to load is usually a portion of the operating system that will coordinate the other software programs.

Operating Systems articles in the Network Encyclopedia

We have several articles available that describe the different types of actual and older Operating Systems.

  • Linux Operating System Unveiled: The Power of the Penguin
    Join us as we dive deep into the Linux Operating System, exploring its rise, robust architecture, and how it has reshaped the landscape of computing.
  • Windows 1.0: Microsoft’s Bold Leap into GUIs [1985]
    Delve into the intriguing history of Windows 1.0, Microsoft’s first graphical user interface. Uncover the revolutionary features, hardware requirements, and the public’s reaction to this groundbreaking release in the mid-’80s.
  • Windows Registry
    Learn what Windows Registry is, how it works, and how to back up, edit and restore it.
    BSD UNIX stands for Berkeley Software Distribution UNIX, a version of UNIX that originated many common UNIX features such as the vi editor, C shell, and TCP/IP networking. BSD UNIX … Read more
  • Windows 2000
    Windows 2000 was a Microsoft operating system built on NT Technology for use on personal computers, business desktops, laptops, and servers.
  • OS/2
    OS/2 is a 32-bit operating system originally developed by IBM and Microsoft as a replacement for MS-DOS. IBM later extended OS/2 to include both server and desktop versions. IBM’s current line of OS/2 software includes the OS/2 Warp Server, the OS/2 Advanced Warp Server, and the OS/2 Warp 4 client.
  • Linux
    Linux is an operating system derived from the UNIX family of operating systems that is POSIX-compliant and freely distributed through many sites on the Internet. Linux was developed in 1991 by a student from Finland named Linus Torvalds, who still controls the development of the Linux operating system kernel.
  • Windows 98
    Windows 98 was Microsoft’s upgrade for users of Windows 95 and earlier versions of Microsoft Windows operating systems. With the code name Memphis, Windows 98 was released on June 25, … Read more
  • UNIX
    UNIX is an operating system developed at AT&T Bell Laboratories in 1969 and widely deployed today in the enterprise networking environment.
  • Windows CE
    Definition of Windows CE in Network Encyclopedia. What is Windows CE? Windows CE is a Microsoft Windows-compatible real-time operating system for a broad range of products including personal and handheld … Read more
  • Windows 95
    Explore the comprehensive history and impact of Microsoft’s Windows 95, from its landmark launch to its incremental releases and integration of Internet Explorer.
  • Microsoft Windows
    Microsoft Windows is a family of operating systems with a common graphical user interface (GUI) that lies at the core of Microsoft’s strategy to make PCs easier to use, reduce the cost of PC ownership, advance the PC platform, and integrate PCs with the Internet.
  • Windows NT
    Windows NT was Microsoft’s most popular operating system for all types of networks ranging from workgroups to enterprise-level installations.
  • Windows for Workgroups 3.11
    Windows for Workgroups 3.11 was a version of Microsoft Windows 3.1 released in 1994 that includes integrated networking components.
  • Windows 3.1
    Windows 3.1 is the GUI-based operating system from Microsoft that made personal computers easier and more fun to use.


Articles posted after being checked by editors.

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