Linux is a Unix-like, open source and community-developed operating system for computers, servers, mainframes, mobile devices and embedded devices. It is supported on almost every major computer platform including x86, ARM and SPARC, making it one of the most widely supported operating systems.
How is Linux operating system used?
Every version of the Linux operating system manages hardware resources, launches and handles applications, and provides some form of user interface. The enormous development community and wide range of distributions means that a Linux version is available for almost any task, and Linux has penetrated many areas of computing.
For example, Linux has emerged as a popular operating system for web servers such as Apache, as well as for network operations, scientific computing tasks that require huge compute clusters, running databases, desktop/endpoint computing and running mobile devices with OS versions like Android.
Since its initial development, Linux has adopted the copyleft stipulations of the Free Software Foundation which originated the GNU GPL General Public License (GPL). Copyleft says that anything taken for free and modified must in turn be distributed for free. In practice, if Linux or other GNU components are developed or modified to create a new version of Linux, that new version must be distributed for free. This is the foundation of open source development which prevents a developer or other groups from profiting from the freely available work of others.
Hundreds of different Linux versions, also known as distributions, are available today. Each is typically tailored for specific target systems, such as servers, desktops, mobile devices or embedded devices. Distributions may be ready-to-use or source code that you must compile locally during initial installation. Community-developed distributions include Debian, Slackware and Gentoo. Commercial distributions include Fedora by Red Hat, openSUSE from SUSE and Ubuntu from Canonical.
The GNU GPL does not prohibit intellectual ownership, and it is commonplace for creators of Linux components to hold copyrights on the various components. The GNU GPL ensures that those components remain free and freely distributed. While the software remains free, however, it is common for some commercial distributions to charge for value-added services, such as support or custom development services.
The Linux operating system follows a modular design that is the key to its many variations and distributions. A bootloader is responsible for starting the Linux kernel. The kernel is at the core of the Linux system, handling network access, scheduling processes or applications, managing basic peripheral devices, and overseeing file system services.
But it is really the many outside developers and GNU projects that offer high-level functions to the Linux kernel to provide a fully realized operating system. For example, there are modules to provide a command line interface, implement a graphical user interface, manage security, offer video input or audio services and many others -- each of which can be modified and optimized to form unique distributions for specific tasks.
Package manager software typically adds, updates or removes software components under the Linux operating system. Examples of package managers include dpkg, OpenPKG, RPM Package Manager and Zero Install.
History of Linux
Linus Torvalds started working on Linux as a replacement to the MINIX operating system while at the University of Helsinki in Finland. Torvalds recognized the work done on the GNU Project in 1983, which intended to create a complete, Unix-compatible operating system comprised entirely of free software, and noted the GNU as a model for distribution. However, the work on GNU had not been finished by the time Torvalds sought a MINIX replacement, prompting him to develop an alternate operating system kernel dubbed Linux -- a contraction of "Linus' Unix" -- and adopt the GNU GPL.
Torvalds released the Linux kernel in September 1991. A community of developers worked to integrate GNU components with Torvalds' kernel to create a complete, free operating system known collectively as Linux. Torvalds continues to develop the Linux kernel, currently at version 4.9, and a vast developer community continues to create and integrate a wide range of components.