What is linux computer

What is Linux?

Overview

Linux® is an open source operating system (OS). An operating system is the software that directly manages a system’s hardware and resources, like CPU, memory, and storage. The OS sits between applications and hardware and makes the connections between all of your software and the physical resources that do the work.

Think about an OS like a car engine. An engine can run on its own, but it becomes a functional car when it’s connected with a transmission, axles, and wheels. Without the engine running properly, the rest of the car won’t work.

How does Linux work?

Linux was designed to be similar to UNIX, but has evolved to run on a wide variety of hardware from phones to supercomputers. Every Linux-based OS involves the Linux kernel—which manages hardware resources—and a set of software packages that make up the rest of the operating system.

The OS includes some common core components, like the GNU tools, among others. These tools give the user a way to manage the resources provided by the kernel, install additional software, configure performance and security settings, and more. All of these tools bundled together make up the functional operating system. Because Linux is an open source OS, combinations of software can vary between Linux distributions.

What’s a command line?

The command line is your direct access to a computer. It’s where you ask software to perform hardware actions that point-and-click graphical user interfaces (GUIs) simply can’t ask.

Command lines are available on many operating systems—proprietary or open source. But it’s usually associated with Linux, because both command lines and open source software, together, give users unrestricted access to their computer.

Our latest release of Red Hat® Enterprise Linux comes with even more built-in command line capabilities than ever before and includes consoles that bundle those capabilities in easy-to-use modules that exist off of the command line.

What does Linux include?

Kernel

The base component of the OS. Without it, the OS doesn’t work. The kernel manages the system’s resources and communicates with the hardware. It’s responsible for memory, process, and file management.

System user space

The administrative layer for system-level tasks like configuration and software install. This includes the shell, or command line, daemons, processes that run in the background, and the desktop environment.

Applications

A type of software that lets you perform a task. Apps include everything from desktop tools and programming languages to multiuser business suites. Most Linux distributions offer a central database to search for and download additional apps.

Linux and open source

Linux is a free, open source operating system, released under the GNU General Public License (GPL). Anyone can run, study, modify, and redistribute the source code, or even sell copies of their modified code, as long as they do so under the same license.

Linux has become the largest open sources software project in the world. Professional and hobbyist programmers from around the world contribute to the Linux kernel, adding features, finding and fixing bugs and security flaws, and providing new ideas—all while sharing their contributions back to the community.

Why choose Red Hat?

Linux is the foundation for the modern IT stack, and Red Hat is one of the leading contributors to the Linux kernel and associated technologies in open source communities. Red Hat engineers help improve features, reliability, and security to make sure your infrastructure performs and remains stable—no matter your use case and workload.

Red Hat Enterprise Linux provides a standard operating environment for everything your enterprise does in every environment—powering the apps that run your business across bare-metal, virtual, containerized, and private and public clouds. Plus, customers running Red Hat Enterprise Linux gain economic advantages of more than US$1 trillion each year, just because of the OS.

Featured resource

Learn more about Linux

• Topic: Understanding Linux
• Article: What is the Linux kernel?
• Article: What’s the best Linux distro for you?
• Article:What is the SAP HANA migration?
• Article: What is a Linux certification?
• Podcast: The rise of Linux
• Topic: Linux containers
• Blog: Red Hat Enterprise Linux blog
• Article: What is open source?

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What is Linux and Why There are 100’s of Linux Distributions?

Last updated October 29, 2020 By Abhishek Prakash 146 Comments

When you’re just starting out with Linux, it’s easy to get overwhelmed.

You probably know only Windows, but now you want to use Linux because you read that Linux is better than Windows as it’s more secure and you don’t have to buy a license to use Linux.

But then when you go about downloading and installing Linux, you learn that Linux is not a single entity. There’s Ubuntu, Fedora, Linux Mint, elementary and hundreds of other ‘Linux variants’. The trouble is that some of them look just like the others.

If that’s the case, why are there so many Linux operating systems? And then you also learn that Linux is just a kernel, not an operating system.

It gets messy. And you may feel like pulling your hair out. As someone with a receding hairline, I would like you to keep your own hair intact by explaining things in a way you can easily understand.

I’m going to use an analogy to explain why Linux is just a kernel, why there are hundreds of types of Linux and why, despite looking similar, they are different.

The explanation here may not be considered good enough for an answer in an exam or interview, but it should give you a better understanding of the topic.

Apologies in advance!

My analogy may not be entirely correct from a mechanical point of view. I’m not knowledgeable about engines, cars and other related mechanical stuff.
But in my experience, I’ve noticed that this analogy helps people clearly understand the concept of Linux and operating systems.
Also, I’ve used the term Linux OS instead of Linux distribution deliberately, so that newcomers don’t start wondering about distributions.

Linux is just a kernel

Linux is not an operating system, it’s just a kernel.

This statement is entirely true. But what does it mean? If you look at books, you’ll find the Linux kernel structure described like this:

Linux Kernel Structure

That is absolutely correct. However, let’s take a different approach. Think of operating systems as vehicles: any kind of vehicle, be it a motorbike, a car or a truck.

What is at the core of a vehicle? An engine.

Think of the kernel as the engine. It’s an essential part of the vehicle and you cannot use the vehicle without it.

But you cannot drive an engine, can you? You need a lot of other stuff to interact with the engine and drive the vehicle. You need wheels, steering, gears, a clutch, brakes and more to drive a vehicle on top of that engine.

Similarly, you cannot use a kernel on its own. You need lots of tools to interact with the kernel and use the operating system. These things could be a shell, commands, the graphical interface (also called desktop environment), etc.

This makes sense, right? Now that you understand this analogy, let’s take it further so that you understand the rest of it.

Windows and other operating systems have kernels too

The kernel is not something exclusive to Linux. You may not have realized, but Windows, macOS and other operating systems have a kernel underneath as well.
Microsoft Windows operating systems are based on the Windows NT kernel. Apple’s macOS is based on the XNU kernel.

Think of operating systems as vehicles

Think of Microsoft as an automobile company that makes a general-purpose car (the Windows operating system) that is hugely popular and dominates the car market. They use their own patented engine that no one else can use. But these ‘Microsoft cars’ do not offer any scope for customization. You cannot modify the engine on your own.

Now we come to the ‘Apple automobile’. They offer shiny-looking, luxury cars at an expensive price. If you have a problem, they have a premium support system where they might just replace the car.

Now comes Linux. Remember, Linux is just an engine (kernel). But this ‘Linux engine’ is not patented and thus anyone is free to modify and build cars (desktop operating systems), bikes (small embedded systems in your toys, TVs, etc.), trucks (servers) or jet-planes (supercomputers) on top of it. In the real world, no such engine exists, but accept it for the sake of this analogy.

• kernel = engine
• Linux kernel = specific type of engine
• desktop operating systems = cars
• server operating systems = heavy trucks
• embedded systems = motorbikes
• desktop environments = body of the vehicle along with interiors (dashboard etc.)
• themes and icons = paint job, rim job and other customizable features
• applications = accessories you use for a specific purpose (like the music system)

Why are there so many Linux OS/distributions? Why do some look similar?

Why there are so many cars? Because there are several vehicle manufacturers using the ‘Linux engine’ and each of them has many cars of different types and for different purposes.

Since the ‘Linux engine’ is free to use and modify, anyone can use it to build a vehicle on top of it.

This is why Ubuntu, Debian, Fedora, SUSE, Manjaro and many other Linux-based operating systems (also called Linux distributions or Linux distros) exist.

You might also have noticed that these Linux operating systems offer different variants but they look similar. I mean look at Fedora’s default GNOME version and Debian’s GNOME version. They do look the same, don’t they?

The component that provides the look and feel in a Linux OS is called the desktop environment. In our analogy here, you can think of it as a combination of the outer body and matching interiors. This is what provides the look and feel for your vehicle, does it not?

Based on the exterior, you can classify the cars into categories: sedan, SUV, hatchback, station wagon, convertible, minivan, van, compact car, 4×4, etc.

But each ‘type of car’ is not exclusive to a single automobile company. Ford offers SUVs, compact cars, vans. etc., and so do other companies like General Motors or Toyota.

Similarly, distributions (Linux OSes) like Fedora, Ubuntu, Debian, Manjaro, etc., also offer different variants in the form of GNOME, KDE, Cinnamon, MATE and other desktop environments.

Ford’s SUV may look similar to Toyota’s or Renault’s SUV. Fedora’s GNOME version may look similar to Manjaro or Debian’s GNOME version.

Some type of cars consume more fuel, some desktop environments need more RAM

You probably understand the ‘usefulness’ of different types of cars. Compact cars are good for driving in cities, vans are good for long trips with family, 4×4 are good for adventures in jungles and other rough terrain. A SUV may look good and feel comfortable to sit in, but it consumes more fuel than a compact car that might not be as comfortable.

Similarly, desktop environments (GNOME, MATE, KDE, Xfce etc) also serve a purpose other than just providing the looks for your Linux operating system.

GNOME provides a modern-looking desktop, but it consumes more RAM and thus requires that your computer has more than 4 GB of RAM. Xfce on the other hand may look old/vintage but it can run on systems with 1 GB of RAM.

Difference between getting desktop environments from the distribution and installing on your own

As you start using Linux, you’ll also come across opportunities to easily install other desktop environments on your current system.

Remember that Linux is a free world. You are free to modify the engine – customize the looks on your own – if you have the knowledge/experience or if you are an enthusiastic learner.

Think of it as like customizing cars. You may modify a Hundai i20 to look like a Suzuki Swift Dzire. But it might not be the same as using a Swift Dzire.

When you are inside the i20 modified to look like a Swiftz Dzire, you’ll find that it may not have the same experience from the inside. The dashboard is different, the seats are different. You may also notice that the exterior doesn’t fit the same on the i20’s body.

The same goes for switching desktop environments. You will find that you don’t have the same set of apps in Ubuntu that you would be getting in Mint Cinnamon. A few apps will look out of place. Not to mention that you may find a few things broken, such as a missing network manager indicator, etc.

Of course, you can put time, effort and skills to make the Hundai i20 look as much like a Swift Dzire as possible, but you may feel like getting a Suzuki Swift Dzire is a better idea in the first place.

This is the reason why installing Ubuntu MATE is better than installing Ubuntu (GNOME version) and then installing MATE desktop on it.

Linux operating systems also differ in the way they handle applications

Another major criterion by which the Linux operating systems differ from each other is package management.

Package management is basically how you get new software and updates for your system. It’s up to your Linux distribution/OS to provide the security and maintenance updates. Your Linux OS also provides the means of installing new software on your system.

Some Linux operating systems provide all the new software versions immediately after their release, while some take time to test them for your own good. Some Linux systems (like Ubuntu) provide an easier way of installing new software, while you may find it complicated in others (like Gentoo).

Staying with our analogy, consider installing software to be like adding accessories to your vehicle.

Suppose you have to install a music system in your car. You may have two options here. Your car could be designed in such a way that you just insert the music player, you hear a click sound and you know it’s installed. Alternatively, you might have to get a screwdriver and then fix the music player in place with screws.

Most people would prefer the hassle-free click-lock installing system. Some people might take the matter (and the screwdriver) into their own hands.

If an automobile company provides scope for installing lots of accessories in click-lock fashion in their cars, they will be preferred, won’t they?

This is why Linux distributions like Ubuntu have more users, because they have a huge collection of software that can be easily installed in matter of clicks.

Conclusion

Before I conclude this article, I’ll also like to talk about support, which plays a significant role in choosing a Linux OS. For your car, you would like to have an official service center or other garages that service the automobile brand you own, wouldn’t you? If the automobile company is popular, naturally it will have more and more garages providing services.

The same goes for Linux as well. For a popular Linux OS like Ubuntu, you have official forums for seeking support and a good number of other websites and forums providing troubleshooting tips to fix your problem.

Again, I know this is not a perfect analogy, but it helps understand things slightly better.

If you are completely new to Linux, did this article make things clear for you, or are you more confused than before?

If you already know Linux, how would you explain it to someone from a non-technical background?

Your suggestions and feedback are welcome.

Like what you read? Please share it with others.

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