The linux operating system is usually found on desktop computers, but not on smartphones or servers.

Every desktop computer uses an operating system. The most popular operating systems in use today are:

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 larger virtual 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 the network.
• 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 PC platforms, 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.

Linux is the best-known and most-used open source operating system. As an operating system, Linux is software that sits underneath all of the other software on a computer, receiving requests from those programs and relaying these requests to the computer’s hardware.

How does Linux differ from other operating systems?

In many ways, Linux is similar to other operating systems you may have used before, such as Windows, macOS (formerly OS X), or iOS. Like other operating systems, Linux has a graphical interface, and the same types of software you are accustomed to, such as word processors, photo editors, video editors, and so on. In many cases, a software’s creator may have made a Linux version of the same program you use on other systems. In short: if you can use a computer or other electronic device, you can use Linux.

But Linux also is different from other operating systems in many important ways. First, and perhaps most importantly, Linux is open source software. The code used to create Linux is free and available to the public to view, edit, and—for users with the appropriate skills—to contribute to.

Linux is also different in that, although the core pieces of the Linux operating system are generally common, there are many distributions of Linux, which include different software options. This means that Linux is incredibly customizable, because not just applications, such as word processors and web browsers, can be swapped out. Linux users also can choose core components, such as which system displays graphics, and other user-interface components.

Who uses Linux?

You probably already use Linux, whether you know it or not. Depending on which user survey you look at, between one- and two-thirds of the webpages on the Internet are generated by servers running Linux.

Companies and individuals choose Linux for their servers because it's secure, flexible, and you can receive excellent support from a large community of users, in addition to companies like Canonical, SUSE, and Red Hat, each of which offer commercial support.

Many devices you probably own, such as Android phones and tablets and Chromebooks, digital storage devices, personal video recorders, cameras, wearables, and more, also run Linux. Your car has Linux running under the hood. Even Microsoft Windows features Linux components, as part of the Windows Subsystem for Linux (WSL).

Who “owns” Linux?

By virtue of its open source licensing, Linux is freely available to anyone. However, the trademark on the name “Linux” rests with its creator, Linus Torvalds. The source code for Linux is under copyright by its many individual authors, and licensed under the GPLv2 license.

The term “Linux” technically refers to just the Linux kernel. Most people refer to the entire operating system as "Linux" because to most users an OS includes a bundle of programs, tools, and services (like a desktop, clock, an application menu, and so on). Some people, particularly members of the Free Software Foundation, refer to this collection as GNU/Linux, because many vital tools included are GNU components. However, not all Linux installations use GNU components as a part of the operating system: Android, for example, uses a Linux kernel but relies very little on GNU tools.

What is the difference between Unix and Linux?

You may have heard of Unix, which is an operating system developed in the 1970s at Bell Labs by Ken Thompson, Dennis Ritchie, and others. Unix and Linux are similar in many ways, and in fact, Linux was originally created to be indistinguishable from Unix. Both have similar tools for interfacing with the system, programming tools, filesystem layouts, and other key components. However, not all Unices are free and open source.

Over the years, a number of different operating systems have been created that attempted to be “unix-like” or “unix-compatible,” but Linux has been the most successful, far surpassing its predecessors in popularity.

How was Linux created?

Linux was created in 1991 by Linus Torvalds, a then-student at the University of Helsinki. Torvalds built Linux as a free and open source alternative to Minix, another Unix clone that was predominantly used in academic settings. He originally intended to name it “Freax,” but the administrator of the server Torvalds used to distribute the original code named his directory “Linux” after a combination of Torvalds’ first name and the word Unix, and the name stuck.

How can I get started using Linux?

There’s some chance you’re using Linux already and don’t know it, but if you’d like to install Linux on your home computer to try it out, the easiest way is to pick a popular distribution designed for your platform (for example, laptop or tablet device) and give it a try. Although there are numerous distributions available, most of the older, well-known distributions are good choices for beginners because they have large user communities that can help answer questions if you get stuck or can’t figure things out. Popular distributions include Elementary OS, Fedora, Mint, and Ubuntu, but there are many others. It's a common saying that the best Linux distro is the one that works best on your computer, so try a few to see which one best suits your hardware and your style of working.

You can install Linux on your current computer (be sure to back-up your data first), or you can buy a System76 or Purism computer with Linux already installed. If you're not looking for the fastest computing experience possible, you can also install Linux on old computers, or buy a Raspberry Pi.

Once you've installed Linux, read our article on how to install applications on Linux, and check back often for news and tutorials on all the best applications open source has to offer. Ultimately, getting started with Linux is a matter of getting started with Linux. The sooner you try it, the sooner you'll get comfortable with it, and eventually you'll blissfully forget that non-open operating systems exist!

How can I contribute to Linux?

Most of the Linux kernel is written in the C programming language, with a little bit of assembly and other languages sprinkled in. If you’re interested in writing code for the Linux kernel itself, a good place to get started is in the Kernel Newbies FAQ, which will explain some of the concepts and processes you’ll want to be familiar with.

But the Linux community is much more than the kernel, and needs contributions from lots of other people besides programmers. Every distribution contains hundreds or thousands of programs that can be distributed along with it, and each of these programs, as well as the distribution itself, need a variety of people and skill sets to make them successful, including:

• Testers to make sure everything works on different configurations of hardware and software, and to report the bugs when it does not.
• Designers to create user interfaces and graphics distributed with various programs.
• Writers who can create documentation, how-tos, and other important text distributed with software.
• Translators to take programs and documentation from their native languages and make them accessible to people around the world.
• Packagers to take software programs and put all the parts together to make sure they run flawlessly in different distributions.
• Enthusiasts to spread the word about Linux and open source in general.
• And of course developers to write the software itself.

Where can I learn more about Linux?

Opensource.com has a huge archive of Linux-related articles. To view our entire archive, browse our Linux tag. Or check out some of our favorites below.