Roles

Linux (i/ˈlɪnəks/ lin-əks[6][7] or /ˈliːnʊks/ lee-nuuks)[8][9][10] is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of Linux is the Linux kernel,[11] an operating system kernel first released on 5 October 1991, by Linus Torvalds.[12][13] Since the C compiler that builds Linux and the main supporting user space system tools and libraries originated in the GNU Project, initiated in 1983 by Richard Stallman, the Free Software Foundation prefers the name GNU/Linux.[14][15] Linux was originally developed as a free operating system for Intel x86-based personal computers. It has since been ported to more computer hardware platforms than any other operating system. It is a leading operating system on servers and other big iron systems such as mainframe computers and supercomputers:[16][17][18][19] more than 90% of today's 500 fastest supercomputers run some variant of Linux,[20] including the 10 fastest.[21] Linux also runs on embedded systems (devices where the operating system is typically built into the firmware and highly tailored to the system) such as mobile phones, tablet computers, network routers, building automation controls, televisions[22][23] and video game consoles; theAndroid system in wide use on mobile devices is built on the Linux kernel. The development of Linux is one of the most prominent examples of free and open source software collaboration: the underlying source code may be used, modified, and distributed—commercially or non-commercially—by anyone under licenses such as the GNU General Public License. Typically Linux is packaged in a format known as a Linux distribution for desktop and server use. Some popular mainstream Linux distributions include Debian(and its derivatives such as Ubuntu and Linux Mint), Red Hat Enterprise Linux (and its derivatives such as Fedora and CentOS), Mandriva/Mageia,openSUSE (and its commercial derivative SUSE Linux Enterprise Server), and Arch Linux. Linux distributions include the Linux kernel, supportingutilities and libraries and usually a large amount of application software to fulfill the distribution's intended use. A distribution oriented toward desktop use will typically include the X Window System and an accompanying desktop environment such as GNOMEor KDE Plasma. Some such distributions may include a less resource intensive desktop such as LXDE or Xfce for use on older or less powerful computers. A distribution intended to run as a server may omit all graphical environments from the standard install and instead include other software such as the Apache HTTP Server and an SSH server such as OpenSSH. Because Linux is freely redistributable, anyone may create a distribution for any intended use. Applications commonly used with desktop Linux systems include the Mozilla Firefox web browser, the LibreOffice office application suite, and the GIMP image editor. Every desktop computer uses an operating system. The most popular operating systems in use today are: * Windows * Mac OS * UNIX Linux is an operating system -- very much like UNIX -- that has become very popular over the last several years. Operating systems are computer programs. An operating system is the first piece of software that the computer executes when you turn the machine on. The operating system loads itself into memory and begins managing the resources available on the computer. It then provides those resources to other applications that the user wants to execute. Typical services that an operating system provides include: * A task scheduler - The task scheduler is able to allocate the execution of the CPU to a number of different tasks. Some of those tasks are the different applications that the user is running, and some of them are operating system tasks. The task scheduler is the part of the operating system that lets you print a document from your word processor in one window while you are downloading a file in another window and recalculating a spreadsheet in a third window. * A memory manager - The memory manager controls the system's RAM and normally creates a largervirtual memory space using a file on the hard disk. (See also this Question of the Day.) * A disk manager - The disk manager creates and maintains the directories and files on the disk. When you request a file, the disk manager brings it in from the disk. * A network manager - The network manager controls all data moving between the computer and thenetwork. * Other I/O services manager - The OS manages the keyboard, mouse, video display, printers, etc. * Security manager - The OS maintains the security of the information in the computer's files and controls who can access the computer. An operating system normally also provides the default user interface for the system. The standard "look" of Windows 98 includes the Start button, the task bar, etc. The Mac OS provides a completely different look and feel for Macintosh computers. Linux is as much a phenomenon as it is an operating system. To understand why Linux has become so popular, it is helpful to know a little bit about its history. The first version of UNIX was originally developed several decades ago and was used primarily as a research operating system in universities. High-powered desktop workstations from companies like Sun proliferated in the 1980s, and they were all based on UNIX. A number of companies entered the workstation field to compete against Sun: HP, IBM, Silicon Graphics, Apollo, etc. Unfortunately, each one had its own version of UNIX and this made the sale of software difficult. Windows NT was Microsoft's answer to this marketplace. NT provides the same sort of features as UNIX operating systems -- security, support for multiple CPUs, large-scale memory and disk management, etc. -- but it does it in a way that is compatible with most Windows applications. The entry of Microsoft into the high-end workstation arena created a strange dynamic. The proprietary operating systems owned by separate companies and the lack of a central authority in the UNIX world weaken UNIX, but many people have personal problems with Microsoft. Linux stepped into this odd landscape and captured a lot of attention. The Linux kernel, created by Linus Torvalds, was made available to the world for free. Torvalds then invited others to add to the kernel provided that they keep their contributions free. Thousands of programmers began working to enhance Linux, and the operating system grew rapidly. Because it is free and runs on PCplatforms, it gained a sizeable audience among hard-core developers very quickly. Linux has a dedicated following and appeals to several different kinds of people: * People who already know UNIX and want to run it on PC-type hardware * People who want to experiment with operating system principles * People who need or want a great deal of control over their operating system * People who have personal problems with Microsoft In general, Linux is harder to manage than something like Windows, but offers more flexibility and configuration options.