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What is Linux?
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.
For the purposes of this page, we use the term “Linux” to refer to the Linux kernel, but also the set of programs, tools, and services that are typically bundled together with the Linux kernel to provide all of the necessary components of a fully functional operating system. Some people, particularly members of the Free Software Foundation, refer to this collection as GNU/Linux, because many of the tools included are GNU components. However, not all Linux installations use GNU components as a part of their operating system. Android, for example, uses a Linux kernel but relies very little on GNU tools.
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.
Companies and individuals choose Linux for their servers because it is secure, and you can receive excellent support from a large community of users, in addition to companies like Canonical, SUSE, and Red Hat, which offer commercial support.
Many of the devices you own probably, such as Android phones, digital storage devices, personal video recorders, cameras, wearables, and more, also run Linux. Even your car has Linux running under the hood.
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:
Ubuntu\'s Unity desktop.
The most popular Linux distributions are:
Each distribution has a different take on the desktop. Some opt for very modern user interfaces (such as Ubuntu’s Unity, above, and Deepin’s Deepin Desktop), whereas others stick with a more traditional desktop environment (openSUSE uses KDE). For an easy guide to Linux desktops check out How to Find the Best Linux Desktop for You.
You can check out the top 100 distributions on the Distrowatch site.
And don’t think the server has been left behind. For this arena, you can turn to:
Some of the above server distributions are free (such as Ubuntu Server and CentOS) and some have an associated price (such as Red Hat Enterprise Linux and SUSE Enterprise Linux). Those with an associated price also include support.
If you’re looking for a server-only distribution, you will also want to decide if you need a desktop interface, or if you want to do this via command-line only. The Ubuntu Server does not install a GUI interface. This means two things – your server won’t be bogged down loading graphics and you’ll need to have a solid understanding of the Linux command line. However (there is always an “however” with Linux), you can install a GUI package on top of the Ubuntu Server with a single command like sudo apt-get install ubuntu-desktop. System administrators will also want to view a distribution with regards to features. Do you want a server-specific distribution that will offer you, out of the box, everything you need for your server? If so, CentOS might be the best choice. Or, do you want to take a desktop distribution and add the pieces as you need them? If so, Debian or Ubuntu Linux might serve you well.
For new users, check out “The Best Linux Distribution for New Users”, to make the selection a much easier task.
Typically, the installation wizards walk you through the process with the following steps (I’ll illustrate the installation of Ubuntu Linux):
Regardless of the name, each of these tools do the same thing – a central place to search for and install Linux software. Of course, these pieces of software depend upon the presence of a GUI. For GUI-less servers, you will have to depend upon the command line interface for installation.
Let’s look at two different tools to illustrate how easy even the command line installation can be. Our examples are for Debian-based distributions and Fedora-based distributions. The Debian-based distros will use the apt-get tool for installing software and Fedora-based distros will require the use of the yum tool. Both work very similarly. I’ll illustrate using the apt-get command. Let’s say you want to install the wget tool (which is a handy tool used to download files from the command line). To install this using apt-get, the command would like like this:
sudo apt-get install wget
The sudo command is added because you need super user privileges in order to install software. Similarly, to install the same software on a Fedora-based distribution, you would first su to the super user (literally issue the command su and enter the root password), and issue this command:
yum install wget
That’s it...all there is to installing software on a Linux machine. It’s not nearly as challenging as you might think. Still in doubt? Recall the Easy Lamp Server Installation from earlier? With a single command:
sudo tasksel
You can install a complete LAMP (Linux Apache MySQL PHP) server on either a server or desktop distribution. It really is that easy.
For the purposes of this page, we use the term “Linux” to refer to the Linux kernel, but also the set of programs, tools, and services that are typically bundled together with the Linux kernel to provide all of the necessary components of a fully functional operating system. Some people, particularly members of the Free Software Foundation, refer to this collection as GNU/Linux, because many of the tools included are GNU components. However, not all Linux installations use GNU components as a part of their operating system. Android, for example, uses a Linux kernel but relies very little on GNU tools.
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, OS X, or iOS. Like other operating systems, Linux has a graphical interface, and types of software you are accustomed to using on other operating systems, such as word processing applications, have Linux equivalents. In many cases, the software’s creator may have made a Linux version of the same program you use on other systems. 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.
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 similar to Unix. Both have similar tools for interfacing with the systems, programming tools, filesystem layouts, and other key components. However, Unix is not free. 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.
Who uses Linux?
You’re probably already using 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 is secure, and you can receive excellent support from a large community of users, in addition to companies like Canonical, SUSE, and Red Hat, which offer commercial support.
Many of the devices you own probably, such as Android phones, digital storage devices, personal video recorders, cameras, wearables, and more, also run Linux. Even your car has Linux running under the hood.
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. Because Linux has such a large number of contributors from across multiple decades of development, contacting each individual author and getting them to agree to a new license is virtually impossible, so that Linux remaining licensed under the GPLv2 in perpetuity is all but assured.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 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.
- Evangelists to spread the word about Linux and open source in general.
- And of course developers to write the software itself.
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 that is designed for your platform (for example, laptop or tablet device) and give it a shot. 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 Debian, Fedora, Mint, and Ubuntu, but there are many others.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.- Do you need programming skills to learn Linux? by Jen Wike Huger
- Test drive Linux with nothing but a flash drive by Scott Nesbitt
- Building a Linux lab and its great potential in education by Don Watkins
- Want a fulfilling IT career? Learn Linux by Shawn Powers
- Install Linux on a used laptop by Phil Shapiro
- 8 Linux file managers to try by David Both
- Who helps your Linux distribution run smoothly? Thank a packager today by Luis Ibanez
- 4 Linux distros for kids by Aseem Sharma
- 6 reasons people with disabilities should use Linux by Spencer Hunley
- The current state of video editing for Linux by Chris Long
- How to do fast, repeatable Linux installations by David Both
What is a “distribution?"
Linux has a number of different versions to suit nearly any type of user. From new users to hard-core users, you’ll find a “flavor” of Linux to match your needs. These versions are called distributions (or, in the short form, “distros.”) Nearly every distribution of Linux can be downloaded for free, burned onto disk (or USB thumb drive), and installed (on as many machines as you like). Ubuntu\'s Unity desktop.Each distribution has a different take on the desktop. Some opt for very modern user interfaces (such as Ubuntu’s Unity, above, and Deepin’s Deepin Desktop), whereas others stick with a more traditional desktop environment (openSUSE uses KDE). For an easy guide to Linux desktops check out How to Find the Best Linux Desktop for You.
You can check out the top 100 distributions on the Distrowatch site.
And don’t think the server has been left behind. For this arena, you can turn to:
Some of the above server distributions are free (such as Ubuntu Server and CentOS) and some have an associated price (such as Red Hat Enterprise Linux and SUSE Enterprise Linux). Those with an associated price also include support.
Which distribution is right for you?
Which distribution you use will depend upon the answer to three simple questions:- How skilled of a computer user are you?
- Do you prefer a modern or a standard desktop interface?
- Server or desktop?
If you’re looking for a server-only distribution, you will also want to decide if you need a desktop interface, or if you want to do this via command-line only. The Ubuntu Server does not install a GUI interface. This means two things – your server won’t be bogged down loading graphics and you’ll need to have a solid understanding of the Linux command line. However (there is always an “however” with Linux), you can install a GUI package on top of the Ubuntu Server with a single command like sudo apt-get install ubuntu-desktop. System administrators will also want to view a distribution with regards to features. Do you want a server-specific distribution that will offer you, out of the box, everything you need for your server? If so, CentOS might be the best choice. Or, do you want to take a desktop distribution and add the pieces as you need them? If so, Debian or Ubuntu Linux might serve you well.
For new users, check out “The Best Linux Distribution for New Users”, to make the selection a much easier task.
Installing Linux
For most, the idea of installing an operating system might seem like a very daunting task. Believe it or not, Linux offers one of the easiest installations of all operating systems. In fact, most versions of Linux offer what is called a Live distribution – which means you run the operating system from either a CD/DVD or USB flash drive without making any changes to your hard drive. You get the full functionality without having to commit to the installation. Once you’ve tried it out, and decided you wanted to use it, you simply double-click the “Install” icon and walk through the simple installation wizard.Typically, the installation wizards walk you through the process with the following steps (I’ll illustrate the installation of Ubuntu Linux):
- Preparation: Make sure your machine meets the requirements for installation. This also may ask you if you want to install third-party software (such as plugins for MP3 playback, video codecs, and more).
Preparing for your Linux installation. - Wireless Setup (If necessary): If you are using a laptop (or machine with wireless), you’ll need to connect to the network, in order to download third-party software and updates.
- Hard drive allocation (Figure 4): This step allows you to select how you want the operating system to be installed. Are you going to install Linux alongside another operating system (called “dual booting”), use the entire hard drive, upgrade an existing Linux installation, or install over an existing version of Linux.
Select your type of installation and click Install Now. - Location: Select your location from the map.
- Keyboard layout: Select the keyboard layout for your system.
- User setup: Set up your username and password.
Installing software on Linux
Just as the operating system itself is easy to install, so too are applications. Most modern Linux distributions include what most would consider an “app store”. This is a centralized location where software can be searched and installed. Ubuntu Linux has the Ubuntu Software Center, Deepin has the Deepin Software Center, some distributions rely on Synaptic, while others rely on GNOME Software.Regardless of the name, each of these tools do the same thing – a central place to search for and install Linux software. Of course, these pieces of software depend upon the presence of a GUI. For GUI-less servers, you will have to depend upon the command line interface for installation.
Let’s look at two different tools to illustrate how easy even the command line installation can be. Our examples are for Debian-based distributions and Fedora-based distributions. The Debian-based distros will use the apt-get tool for installing software and Fedora-based distros will require the use of the yum tool. Both work very similarly. I’ll illustrate using the apt-get command. Let’s say you want to install the wget tool (which is a handy tool used to download files from the command line). To install this using apt-get, the command would like like this:
sudo apt-get install wget
The sudo command is added because you need super user privileges in order to install software. Similarly, to install the same software on a Fedora-based distribution, you would first su to the super user (literally issue the command su and enter the root password), and issue this command:
yum install wget
That’s it...all there is to installing software on a Linux machine. It’s not nearly as challenging as you might think. Still in doubt? Recall the Easy Lamp Server Installation from earlier? With a single command:
sudo tasksel
You can install a complete LAMP (Linux Apache MySQL PHP) server on either a server or desktop distribution. It really is that easy.
