Linux is an operating system that is very often used in servers. Its main advantage is that it is available for free, or for a very small fee (depending on the distribution). Linux was invented by Linus Torvalds, based on Minix, which was a clone of Unix. There are other operating systems based on Unix, such as FreeBSD. Linux itself is really just the kernel, but that is the name given to the entire operating systems that run on that kernel.

The main component of Linux is the Linux kernel, which is the kernel of the operating system released by Linus Torvalds in 1991. Linux was originally developed for personal computers based on the x86 architecture. Since then, it has become the most ported operating system – in fact, Linux has appeared on significantly more hardware platforms than any other operating system. Over 90% of today's 500 supercomputers also run some variant of Linux, including the top ten most powerful.

The Android operating system is also built on the Linux kernel, which is found on many mobile devices – smartphones and tablets. Versions of Linux can also be found on video game consoles (e.g. PlayStation 3 uses the Yellow Dog distribution), televisions, network routers, phones, etc. The widespread adoption of various Linux distributions is due to the widespread market for netbooks, where Linux was chosen both for its price (free) and its low hardware requirements.

Linux is based on Unix, the development of which began in 1969 in the AT&T labs. Linux was first released in 1971. Back then, it was written entirely in assembly language. In 1973, it was rewritten entirely (except for the kernel and I/O) in the C programming language. A decade later, in 1983, the so-called GNU Project began, with the goal of creating a complete Unix-based software operating system composed entirely of free software.

Users can control Linux either through a command line interface (CLI) or a graphical user interface (GUI). It is the proliferation of user-friendly and modern graphical interfaces that has helped Linux's expansion somewhat. On desktop computers, the most common graphical extensions are KDE Plasma Desktop, GNOME, or Xfce. The most popular graphical extensions are those that are as close as possible to the Microsoft Windows graphical environment.

Linux distributions are collections of system and application software that are available for free. Together with a particular graphical interface, they form a so-called Linux distribution. Most Linux distributions are available for free, but there are some that are only available for money.

Linux has a clear predominance on servers and with hosting companies. Often we can also see FreeBSD Linux, which is also used by Hosting Blueboard.cz. Linux is also gaining a large share on mobile devices, mainly thanks to Google's Android. As such, Android is based on the Linux kernel. The success of Linux on mobile devices is clearly due to its low hardware requirements and zero cost, similar to netbooks.