This feature first appeared in the Fall 2019 issue of Certification Magazine. Click here to get your own print or digital copy.

Picture yourself sitting down to use Linux. Now picture yourself wondering what Linux distro you will be using. The picture just got more complicated. In the 28-year history of Linux, there have been nearly 800 distros, or distributions. Nearly 300 are still in use.

Well, what is a distribution in Linux? Why are there so many of them, and what makes them all different from one another? Are they all kind of the same or do they differ widely — so widely, maybe, that you can't even utilize one in the same manner as another? If you're a business, which one would you choose? And is the answer different if you're an individual user?

There are so many factors underlying your choice of Linux distribution that you really need to make an informed decision. Then again, all Linux distributions are free, and only a relatively small number of them have cost strings attached (typically in the form of support and customer service). So if you don't choose wisely at first, then you probably haven't lost much.

What's in a distro?

Let's begin by discussing what a Linux distribution actually is. With a traditional Windows or Mac operating system (OS), you get a LOT of software code, compiled into a very large and distributable package — but it comes as a single operating system. You install the current version of Windows (10) or macOS (10.15) on your laptop or desktop.

Linux is an entirely different animal and works much differently than a traditional operating system. Distributions (or distros) are different versions of Linux based on the original Linux kernel. Also, a typical Linux operating system (or distribution) isn't produced by a single organization. Separate and distinct organizations and individuals work on different parts.

There's the Linux kernel (the core of any distro), the GNU shell utilities (the terminal interface and many of the commands you use), the X server (which produces a graphical desktop), the desktop environment (which runs on the X server to pro- vide a graphical desktop), and more. Beyond that, you have all kinds of different tools, developed by thousands of teams and individuals across the world.

For example, there are system services, graphical programs, terminal commands, and so forth. Many are developed independently from one another and as they get spread around, they are further reiterated on and grown.� Linux distributions do the hard work for you, taking all the code from the open-source projects and compiling it for you, combining it into a single operating system you can boot up and install: a true OS.

Distros also make choices for you, such as choosing the default desktop environment, browser, and other software. Most distributions add their own finishing touches, such as themes and custom software, many of which you can choose to install or not install. Some are so well written and tight in their code that enterprising entrepreneurs pick them up and package them, with full releases and full companies built around them.

Why are there so many distros?

Now that you understand what a distribution is and what makes up a distribution (the combo of everything released as a package), you may ask yourself: Why are there so many and how many actually have a significant user base or support? To tackle that first question first, the answer is obvious: There are so many people in the world, you couldn't possibly make one thing that would please them all.

Another equally obvious factor is that there are so many creative people in the world. People love to invent and to change things. They love to create new utilities, tools, graphical user interfaces. There is no upper limit to the number of things people make, so really there is no theoretical upper limit to the number of distributions.

Big dog distros

The first question to ask when choosing a distro is what you want to use is for — what is the purpose for which you are installing a distribution in the first place? Well, if you want to go mainstream and get one of the handful of big distros that are all-in-one operating systems, then you could go with Ubuntu. Ubuntu is an open source OS that runs from the desktop, to the cloud, to all of your connected things.

Ubuntu is the most widely used Linux operating system out there. If you want millions of users continually playing around in your OS, developing new things for your OS, or you just want to follow where others have beaten a well-trodden path, then you should go with Ubuntu.

On top of being perhaps the most thoroughly developed distribution out there, Ubuntu has millions of individuals developing additional features that amplify the operating system, and which you can simply download via a snap-in manager.

The second-biggest of the King of the Hill distros is probably Red Hat Enterprise Linux (RHEL). If you haven't heard of this one, then you may live under a rock. RHEL is one of the most widely used operating systems out there for the Windows-averse crowd. (RHEL is derived from Red Hat's Fedora distro. Of note, Linus Torvalds, the creator of the original Linux kernel, has said in the past that he uses Fedora himself.)

RHEL is compiled, distributed throughout a network, very stable (most agree), and has tight enough security to run a business on — all while still maintaining a graphical user interface. (You have to throw a bone to the masses that still love their Windows and macOS simplicity.)

Into the deep end

If you want a super lightweight distro with very low overhead, then you may want to get MX Linux. This lightweight distribution allows an admin or user to have older PCs or devices. You need very little in terms of system resources to boot this thing up and I have seen this distribution run on a USB key. (Don't forget, some of these distributions were originally developed for nefarious reasons.)

What if you have a novice user base or beginning Linux pupil? You could try Linux Mint. Mint comes packed with much of the software you need to get straight back into your workflow, such as LibreOffice and some decent onboard media software. You have a choice of four main desktop environments, with Cinnamon being the most Windows-like. Mint is pretty light resource-wise, too, loading faster and using less memory than the all-popular Ubuntu.

Are you a hard-core hacker? Well, Kali or BackBox would be the best for you. They are the best used for ethical hacking (the only kind you should do) and for penetration testing, or the act of trying to infiltrate an organization's cyber defense. They are also both very good for forensics and hard drive examination. These distros are on the right side of the law, so to speak.

Maybe you enjoy feeling like you're not being watched. If you like a secure lifestyle, then you could load Tails and be configured with the Tor browser. Tor is a public decentralized network that allows users to send and receive traffic through several relays. The concept is very simple: each relay has its own IP address which hides the original location of the user by creating several layers.

This is especially useful for privacy-conscious individuals or users within countries that have oppressive governments. Tails is designed to be run from portable storage, meaning that it only uses your RAM and leaves no permanent traces of what you've been up to on it. If you are using this distribution, then you are most likely not the target of this article.

Administrator or end user?

If you are a system administrator making the call for an entire organization, then you should choose carefully. You certainly don't want to choose something that will cause you a lot of work later, or get you in trouble with your boss, or otherwise sow the seeds of disaster. Your distro should have a high level of security and function, be distributable on an internal network, and be easily manageable from a central location.

This writer, in those shoes, would choose RHEL. Let's face it, no one gets fired for choosing Red Hat. It's secure and stable, generally as simple as if you were installing Windows in your network, and you can still feel a little like you're thumbing your nose at the OS establishment while coughing up a fee to receive the benefit of professional support.

For individual use, the sky (and your imagination) is the limit. Install whatever you like and for whatever (legal) purposes you require. I personally love the distributions that boot from a USB key or are super lightweight. Ethical hacking and penetration testing is a very cool employment track and the distributions (noted above) that help with that are also top notch in my book right now.

The truth is that there are so many different distributions, each with their own nuances and focus, that we couldn't possibly cover all of them. What you do with them will vary, but maybe now you have a better idea of what they are and how you can choose which one is right for you and your organization.

If you want to get really picky with your distribution, of course, then you can go ahead and customize whatever you download. That's a big part of the magic of Linux. The more that you know and understand about Linux — or are willing to learn — the less that you are required to live in the box that your distro of choice shows up in. Good luck getting your hands dirty!