Linux is not an Operating System. It’s a collection of OSes, commonly used for development, servers, and a free alternative to costly OSes like Windows and macOS.
Open and Closed Source Software
Let’s define two things: open-source and closed-source software.
The code that you write in C, Java, or any other higher-level programming language is called source code (read more about it here).
When you translate code from one language (such as C++ or Java) to another (most commonly machine language/binary), the operation is irreversible. You can’t take binary code and turn it back into C code.
This means that unless the source code for compiled software is published publicly, the software is closed-source: the code that powers it is known only to the creators of the software. This is also called proprietary software, and it enables the makers of software to be able to sell it without having someone reverse-engineer it and create a better alternative (which could then steal their business).
Open-source software is just the opposite: the software’s source code is completely public and modifiable.
A Brief Computing History
Back in the early 1970s, AT&T developed a proprietary Operating System for their internal use (with the help of Bell Labs). This OS was called UNIX. AT&T eventually sold its rights to UNIX, but not before the companies to which they licensed the OS created derivatives of it (for example, UC Berkely and Apple).
In 1983, the GNU Project was created as a free software initiative meant to give users complete freedom and control over their computing devices. Part of the project is the GNU Operating System, which functions much like UNIX but is completely open-source.
However, the GNU OS was missing one thing: a functioning kernel. A kernel is a piece of software responsible for connecting the software on the computer and the hardware powering the computer.
So, when in 1991, the Linux kernel was created by Linus Torvalds, people began substituting the unstable GNU kernel with the Linux kernel (which is also open-source).
And thus, GNU/Linux was born (more commonly known today as simply Linux).
A GNU/Linux OS is called a distribution. One of the most popular distributions is Ubuntu, which is partially closed-source but known as being excellent for Linux beginners.
Some Linux distributions include:
- Xubuntu (community-maintained open-source version of Ubuntu)
- Debian (open-source OS which Ubuntu is based on)
Given that GNU/Linux is made entirely from open-source software, it’s possible to make your own Linux distribution. Linux From Scratch is an excellent guide to building your own Linux OS.
Why Does This Matter?
If you ever want to escape the propreitary environment of Microsoft’s Windows and Apple’s macOS, Linux is the best alternative OS. It’s also quite useful for programming and development.