All about Linux. What can I do in Linux? What is a Linux distribution? Are there really no viruses on Linux? Linux really that secure?

What is Linux? This question is difficult and has about 3 answers, almost all correct.

1. Linux is an operating system. GNU / Linux is an operating system. The GNU / Linux operating system consists of the Torvalds kernel (Linux) and the GNU suite of applications. The suite of applications mainly includes a compiler, various utilities that allow the operation and programming of the computer running Linux. (I mean programming how the PC works, not necessarily writing code)
2. Linux is a kernel. Yes. The word Linux alone means the core of the operating system, but many people when talking about Linux refer to a distribution. If I used GNU / Linux as an example in the first explanation, then I will tell you about GNU / Hurd. Hurd is also a kernel, over which runs the GNU suite of applications. PS: The kernel is the one that connects the user-space (user space, applications that are accessible to the user) and hardware. If the user creates a file on disk, the application interacts with the kernel, tells it what the user wants and the kernel sends the command to the hardware.
3. Linux is a distribution. Mmm, yes. It's not very fair to say that, but we can do it. However, most Linux distributions have the name "Linux" in them.

What is a Linux distribution?
A Linux distribution is an operating system, a suite of applications running under the Linux kernel.

And yet, what is a Linux distribution?
It's an operating system, like Windows or MacOSX. It's that suite of GNU applications (and not only) put in a big and beautiful package so that the user can use them immediately after installing the system. It's the kernel + user-space, where user-space differs from distro to distro.

I didn't quite understand, but either. However, why are there so many distroes? What sets them apart?
Uh. Good question ... There are many distributions because it is possible. I think that would be the best answer to this question. What sets them apart? Almost nothing, and everything. Because basically a set of standard applications and the Linux kernel all run, they're all pretty much the same. They are mainly distinguished by the kernel version, the package manager (if any), the set of applications they come with pre-installed, the interface and the reason why they were created. When I say reason, I mean more the target users. There are specialized distro for penetration testing, distro for routers, servers, more recently we have a distribution dedicated to PC games (SteamOS), for MediaCenters, etc.

And if a distribution is for servers, can I use it only on servers? Or if I install a specific MediaCenter distro on my PC, will I only be able to use my PC as a MediaCenter?
We have two questions and about the same idea. The answer is: no. I had an ftp server running on the laptop I was working with every day. Also, the server distro itself runs a set of applications designed specifically for servers, this does not mean that an interface / desktop environment (DE) cannot be installed.

Desktop environment?
Do you know Windows users who customize their system by changing themes and more? With a DE you can completely change your interface. It's like switching from W7 without Metro interface to W8 with Metro interface, but under the hood runs your favorite distribution.

More day of distros and what differentiates them.
Well, there is a lot to say and it should be explained for each distro separately. For example we take Debian. His mother's Debian is more of a server distro. Why? Because it has several repositories from which you can choose and each one is intended for other users. By default, Debian comes with "stable" reps. This means that all the packages here have been tested and paratested against security breaches and any breaches have been blocked, the versions of the packages (programs) here are stable and older, there are not many bugs, the updates are slow. Besides stable, there is also testing and experimental. Testing has newer packages, packages that have not been tested so thoroughly, packages that have new functions in them and are being tested. (we could say beta versions) Ubuntu is based on Debian testing.

Repository and package manager?
It's simple here. Repo / repository means a "market" of applications running under Linux. The repo is specific to each distribution, more or less due to the way the packages are packaged. If in Windows we had * .cab or * .msi to install the applications, in Linux we have * .deb, * .pkg, * .rpm, * .xz, etc. and each file type is recognized by a single type of package manager (installer).

Does that mean I can't install a * .pkg with a package manager that only knows about * .deb?
Exact. But don't worry. Usually the application you need is just a simple remote control. More than likely there is the package in the distro market.

How do I install a * .tar or * .tar.gz or * .gz package?
Simple. You do not install it. There are no such packages. Those are the sources of archived programs. It is best to look for the program in the distribution market and install it from there.

Couldn't they be put in a zip archive or rarely?
Mmm, not really. I pray. They could be put on, but let's just say it's common, plus the zip doesn't offer such a good compression algorithm for text files.

How many DEs are there after all? Can any distribution be installed with a certain DE?
There are about 3-4 DEs known and used most often: Gnome, KDE, Xfce, Lxde, Unity (exclusively Ubuntu)
These can be installed in any distribution, except Unity. It just doesn't work well on anything other than Ubuntu. (I do not go into details)
I'm currently running Gnome on ArchLinux. Last year I had KDE, but one of them never caught my eye with KDE. It's more a matter of taste.

What can I do in Linux?
The correct question would be "what can't I do in Linux and I could in Windows", and the answer is: it depends.
First of all, the big shock of many is that they can't open * .exe files by default. (hence the fact that Linux does not catch viruses)
Second, there are alternative programs to Windows. Plus, there's a program called Wine that runs Windows on Linux. It's complicated to explain, but in principle, you can do 90% of the things you did in Windows, and through Wine, the percentage can even reach 95-97%.

Are there really no viruses on Linux?
I dont say that. I just said it doesn't catch or viruses as often and easily as Windows. Basically, since you can't open * exes by default, you can't open viruses either. There are viruses on Linux, but they are very rare and the chances of catching one are lower than you think.

But you said that through Wine it goes to open exes, doesn't that mean that if I open a virus through Wine, I will virus my Linux?
Not. That means you don't virus anything. Basically ... the only thing that virus can do is limited to the folder where Wine runs (usually in /home/$USER/.wine) and the partitions that Wine has access to. If the virus wants to delete system32, then it will succeed, but if for example it wants to inject its code into an executable or read the memory of another executable that also runs through wine, it will not be successful, because even if Wine "emulates "Windows, subject to * nix rules and permissions. (Where one application doesn't know another application) Is

Linux really that secure?
Depends on what you mean. Yes and no. It is useless to run Linux if you have a firewall open and invite the world to a VNC.
Let's say that a Linux installation as it is, without any modification and with up-to-date updates, is much more secure than a Windows.
As we see here, many exploits are for Windows, not Linux.

But Linux is hard!
Not. Linux is not hard. It's hard to go from the usual to something new. Nah. Imagine you are an Apple fan and you and your kids don't know what Windows is. You only have Macs in the house. You are all in front of a Windows PC for the first time in your life.
"Windows is hard! There's nothing I know about this system!"
Exact. It's nothing you know about Mac in Windows, because you've only used Mac so far.

But the command line, I don't know that!
You are not obliged and no one makes you use the terminal if you do not want to. Nowadays (even in 2007, when I first tried Linux on my home PC) you don't have to do that. MacOS also has a shell and a terminal, but I haven't seen hipsters through Starbucks walk into the CLI. (command line interface)

Ok. I took my heart in my teeth and tried Linux. I also want to try the terminal. I took orders from the net, but they don't work!
First of all, you don't take "orders" from the net and execute them without knowing what they are doing, otherwise you end up like these. Second, commands are not executed without thinking about them. It's a reason why that line doesn't work, and more than likely the reason is written as an error message, immediately after pressing the "enter" key.
Think before you press enter.
A funny thing: "Can rm rm rm?" "Yes."
Can the file deletion utility (rm from remove) be deleted on it? The answer is yes, because rm deletes files. In the same way you can run out of the package manager or the graphical interface and you panic and reinstall the system when the solution is very, very simple. Basically, the computer will do exactly what it is told.

What do you think about Android?
Well, Android is by definition a Linux distribution. It is based on the Linux kernel and some utilities (ls / dd / cat / cd / mount whatever) and runs on ARM processors. My real opinion about Android? If it's not pure Android the way Google wanted it, or an independent or community-supported project based on pure Android, then it's all crap. This is the cruel truth. Samsung sux, HTC sux, LG sux, whaterver Android ROM from a known phone manufacturer sux. Fragmentation of Linux devices and distros is a real problem. (I'm not referring to disk fragmentation, but to the multitude of existing distro variants) Ah. And I find it awful to run a Java virtual machine over Linux. It's very crazy and penalizes performance, but ... nah.

Are there other devices running Linux besides Android phones?
Yes. A lot. You probably won't even realize it. Sony TVs know that they had the Linux kernel on some models, a lot of router models, iOS5 with jailbreak (cydia) has the Debian package manager (dpkg), RATB GPSs, Metro and airport InfoTVs, etc. . My guess is that any device that has the label "smart *" on it runs if not Linux, a system based on * nix.

Did you say something fragmentary?
Yes. But not the Windows one. The concept and the idea are about the same. I will not go into details about how file system fragmentation occurs, but I know that there is a myth that fragmentation in Linux does not exist. Total false. It exists, but
1. it is not so visible
2. it does not affect the performance because ...
3. because the kernel and file system was designed to try to reduce fragmentation. In my opinion, they were successful. However, in 2013 about 50% of PC users have SSDs and fragmentation on SDD is imperceptible. (Even 0, actually)
The problem is that the kernel knows how to reduce the problem of fragmentation on Linux-specific file systems. So if you write to an NTFS partition, the fragmentation will appear.

Linux specific file systems?
Ext / 2/3/4, btrfs, reiserfs, xfs, etc. The best known is EXT / 2/3/4 and the most used at the moment is EXT4.

Does Linux see Windows partitions? But does Windows see Linux partitions? Not realy. Not by default. Ok, it depends on the distro and we will divide the answer into two parts.1. User-friendly distro (like Ubuntu / SuSe / Fedora) and any distro that does not require more careful installation and configuration recognizes, mounts, writes and reads specific Windows file systems: FAT16 / 32 and NTFS. (Probably ExFAT, but I'm not sure). The other distro need a driver (ntfs-3g) for the kernel to know what to do with the NTFS partitions. Recognition of FAT16 / 32 file systems is included in the kernel.2. Windows, like Linux, without a driver does not recognize the SDF in Linux. There is driver only for EXT / 2/3/4.

Why do you use Linux?
Uh ... I could answer this question with "Because my current phone is running Android and it's not old enough to change it. Also the router is running Linux and I'm very happy with it."

That's not what I meant! Why do you like the X distro? What do you like about Linux (as an OS)?
Aaa. What I like? Freedom. The fact that I can do one thing in 20 ways. The fact that through a written command in the terminal I have the updated system up to date. It's a lot to tell, but mainly that it works. It just works. More details.

What distro do you use, what distro did you use?
I started with Ubuntu and now I have ArchLinux. I went through Mint, SuSe, Fedora, but I always get into my first two loves: ArchLinux and Ubuntu. I still prefer the rolling-release model, so I could probably say I'm an ArchLinux fan (boy).
And if that's not enough, see here. [: D]

Who would you recommend Linux to?
Sincere? Anyone ... The right question is "who would recommend trying the X / Y / Z distribution".
Given that Android is a Linux distribution and is present at least 100 meters around us, I could say that even the worst person with an Android phone knows how to use a Linux distribution.
I ask you: what do you mean by Linux? X / Y / Z distro? The CLI? The kernel?
Distributions can be put on a USB stick and can be tried Live! without affecting the PC / laptop. The CLI is more difficult, but ... I don't know how to manage Windows via CMD either and most of them use Windows, but I haven't heard them complain that I don't know how to play with CMD. (See the question in post 1, the one with the terminal)
I don't think you thought about the kernel.