Linux is an open source operating system. An operating system is the software that directly manages a system’s hardware and resources, like CPU, memory, and storage. The OS used as a medium in between applications and hardware and makes the connections between all of your software and the physical resources that do the work.
How does Linux work?
Linux was designed to be similar to UNIX, but has evolved to run on a wide variety of hardware from phones to supercomputers. Every Linux-based OS involves the Linux kernel—which manages hardware resources—and a set of software packages that make up the rest of the operating system.
The OS includes some common core components, like the GNU tools, among others. These tools give the user a way to manage the resources provided by the kernel, install additional software, configure performance and security settings, and more. All of these tools bundled together make up the functional operating system. Because Linux is an open source OS, combinations of software can vary between Linux distributions.
What is a command line?
The command line is your direct access to a computer. It's where you ask software to perform hardware actions that point-and-click graphical user interfaces (GUIs) simply can't ask.
Command lines are available on many operating systems—proprietary or open source. But it’s usually associated with Linux, because both command lines and open source software, together, give users unrestricted access to their computer.
Linux and Opensource
Linux is a free, open source operating system, released under the GNU General Public License (GPL). Anyone can run, study, modify, and redistribute the source code, or even sell copies of their modified code, as long as they do so under the same license.
Linux has become the largest open sources software project in the world. Professional and hobbyist programmers and developers from around the world contribute to the Linux kernel, adding features, finding and fixing bugs and security flaws, live patching, and providing new ideas—all while sharing their contributions back to the community.