If you're new to Linux, you might think it's an operating system. It's not true. Linux is actually only the kernel, the core of an operating system.
The kernel allows any software (whatever you see on the screen) to interact with the hardware (whatever you touch with your hands). Without a kernel or kernel, your system may not work.
So when you say Linux, you are not referring to any of the Linux kernel-based operating systems, such as Ubuntu or Fedora. As a kernel, Linux can do nothing on its own.
What is needed is the involvement of some to connect it with all the software necessary to provide a complete experience. When this happens, the resulting operating system running on a Linux kernel is also known as a distribution (or distro).
What makes Linux different?
Why is the Linux kernel different? Like most applications running the Linux kernel, the kernel is actively maintained by a free and open source software community (FOSS from free and open source software).
Open source software is free and everyone can view the source code and modify it as they wish.
This means that specialist developers from around the world contribute to each FOSS project either for free or through sponsorships from companies such as Canonical and Red Hat.
Αντίθετα, ο πηγαίος κώδικας των Windows δεν είναι διαθέσιμος σε κανέναν εκτός από τους προγραμματιστές της Microsoft και αποτελεί αδίκημα κάθε decompile ή reverse engineering (αντίστροφη engineering, τεχνική των crackers).
So you can not build your own kernel for Windows, fix bugs, or distribute an enhanced version of Windows that you created.
Το Linux είναι εντελώς διαφορετικό και ο λόγος είναι η Γενική Άδεια Δημόσιας Χρήσης gnu (GNU General Public License).
This license provides the legal background for your rights to the software. Originally written by Richard Stallman, it ensures that even when a work is modified or improved, it remains public for its use by others. It is the most widespread license of the FOSS community.
Dangers
The nature of free licenses and open-source software can be a double-edged sword. It does not offer a clear revenue model, so growth may be inconsistent.
So we notice that some programs receive updates very often, while others remain idle for years.
However, Linux has now spread and become the backbone of the internet. It is the most common operating system for supercomputers.
But what is it that attracts people to Linux distributions? 
It is effective: Many Linux distributions come from decades of experience in server rooms. System administrators often appreciate the sleek, simple code that simply does the job without wasting processing power. Server rooms are a very harsh and demanding environment which has made Linux distributions much better, more secure and more durable.
It is customizable: Linux distributions allow their users to modify everything in the system. There are distributions that allow you to select different pieces of software to assemble your own system.
Many distributors encourage you to make your own customizations, although minor changes to the basic operating system require more specialized knowledge.
It's free: The vast majority of Linux distribution software is free.
It is modular and specialized: You can customize a system to suit your needs: remote video monitoring, playback centers medium, servers, workstations and much more according to your needs.
It does not track or collect you data: All distributions pay close attention to the privacy of their users. But since the confirmation of the rule needs the exception, let us mention that Canonical this year decided to collect some of its users' data;
