Operating Systems

Operating Systems

• Operating system and its fuctions

An operating system (OS) is the software that manages the sharing of the resources of a computer 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. At the foundation of all system software, an operating system performs basic tasks such as controlling and allocating memory, prioritizing system requests, controlling input and output devices, facilitating networking and managing file systems. Most operating systems come with an application that provides a user interface for managing the operating system, such as a command line interpreter or graphical user interface. The operating system forms a platform for other system software and for application software.

The most commonly-used contemporary desktop and laptop (notebook) OS is Microsoft Windows. More powerful servers often employ Linux, FreeBSD, and other Unix-like systems. However, these Unix-like operating systems, especially Mac OS X, are also used on personal computers.

• Types of operating systems : (Windows, Unix, Linux, etc. for pc/mini/mainframe)

Microsoft Windows is the name of several families of software operating systems by Microsoft. Microsoft first introduced an operating environment named Windows in November 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces (GUIs).^[1] Microsoft Windows eventually came to dominate the world’s personal computer market, overtaking Mac OS, which had been introduced previously. At the 2004 IDC Directions conference, IDC Vice President Avneesh Saxena stated that Windows had approximately 90% of the client operating system market.^[2] The most recent client version of Windows is Windows Vista. The current server version of Windows is Windows Server 2003. The successor to Windows Server 2003, Windows Server 2008, is currently being beta tested.

UNIX

Unix (officially trademarked as UNIX®, sometimes also written as Unix or Unix® with small caps) is a computer operating system originally developed in 1969 by a group of AT&T employees at Bell Labs including Ken Thompson, Dennis Ritchie and Douglas McIlroy. Today’s Unix systems are split into various branches, developed over time by AT&T as well as various commercial vendors and non-profit organizations.

LINUX

Linux (pronounced IPA: /ˈlɪnəks/ in English; variants exist^[1]) is a Unix-like computer operating system. Linux is one of the most prominent examples of free software and open source development; typically all underlying source code can be freely modified, used, and redistributed by anyone.^[2]

The name “Linux” comes from the Linux kernel, started in 1991 by Linus Torvalds. The system’s utilities and libraries come from the GNU operating system, started in 1983 by Richard Stallman. The GNU contribution is the reason for the alternative name GNU/Linux.^[3]

Predominantly known for its use in servers, Linux is supported by corporations such as Dell, Hewlett-Packard, IBM, Novell, Oracle Corporation, Red Hat, and Sun Microsystems. It is used as an operating system for a wide variety of computer hardware, including desktop computers, supercomputers,^[4] video game systems, such as the PlayStation 2 and PlayStation 3, several arcade games, and embedded devices such as mobile phones and routers.