A2ZComputerParts

An operating system is the software component of a computer system that is responsible for the management and coordination of activities and the sharing of the resources of the computer. The operating system (OS) acts as a host for application programs that are run on the machine. As a host, one of the purposes of an operating system is to handle the details of the operation of the hardware. This relieves application programs from having to manage these details and makes it easier to write applications. Almost all computers, including hand-held computers, desktop computers, supercomputers, and even modern video game consoles, use an operating system of some type. See also Computer systems architecture.

Operating systems offer a number of services to application programs and users. Applications access these services through application programming interfaces (APIs) or system calls. By invoking these interfaces, the application can request a service from the operating system, pass parameters, and receive the results of the operation. Users may also interact with the operating system by typing commands or using a graphical user interface (GUI, commonly pronounced “guoey”). For hand-held and desktop computers, the GUI is generally considered part of the operating system. For large multiuser systems, the GUI is generally implemented as an application program that runs outside the operating system. See also Computer programming; Human-computer interaction.

Common contemporary operating systems include Microsoft Windows, Mac OS X, AmigaOS, Linux and Solaris. Microsoft Windows has a significant majority of market share in the desktop and notebook computer markets, while the server and embedded device markets are split amongst several operating systems.

The designs of the aforementioned operating systems, including Windows (especially Windows NT), were inspired by, directly inherited from, or are very similar to the UNIX operating system. UNIX was developed at Bell Labs beginning in the late 1960s and spawned the development of numerous free and proprietary operating systems.

An operating system (OS) manages computer resources and provides programmers with an interface used to access those resources. An operating system processes system data and user input, and responds by allocating and managing tasks and internal system resources as a service to users and programs of the system. An operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating computer networking and managing files.

Common contemporary desktop OSes are Linux, Mac OS X, Microsoft Windows and Solaris. Windows is most popular on desktops while Linux is most popular in server environments. The desktop computer operating system market is currently dominated by Microsoft Windows which holds around 90% of the market. Because of its popularity, Windows is often considered synonymous with the PC; software that is categorized as supporting the PC platform often only runs on Windows. Linux, Mac OS X and MS Windows all have server and personal variants. With the exception of Microsoft Windows, the designs of each of the aforementioned OSs were inspired by, or directly inherited from, the Unix operating system. Unix was developed at Bell Labs beginning in the late 1960s and spawned the development of numerous free and proprietary operating systems.