UNIX, LINUX, GNU

UNIX is an umbrella term that groups many operating systems used in big corporations and institutions, starting from the 70's.

• Under the hood macOS and iOS is a UNIX Operating System.
• Android is based on (a modified version of) Linux.

GNU/Linux is a free alternative to UNIX.

• It is a Unix clone, multi-tasking and a multi-user operating system that was developed by Linus Torvalds with the collaboration of the developers around the world.

Linux is an operating system, like macOS or Windows.

• Linux is a kernel, not an entire operating system. A kernel provides access to computer hardware and a controlled access to system resources.
• The Linux "core" (called a kernel) born in 1991 in Finland, went on to be the kernel of the GNU Operating System, creating the duo GNU/Linux.
• Microsoft has an official Windows Subsystem for Linux (WSL) which you can (and should!) install on Windows. This will give you the ability to run Linux in a very easy way on your PC.

It powers the vast majority of the servers that compose the Internet. It's the base upon which everything is built.

• For the vast majority of the time you will run a Linux computer in the cloud via a VPS (Virtual Private Server) like DigitalOcean.

Linux is also special because there's not just "one Linux", like is the case with Windows or macOS. Instead, it have distributions.

• A "distro" is made by a company or organization and packages the Linux core with additional programs and tooling.
• Its based upon linux kernel and often a package management system and additional programs and tooling.
• eg. Debian, Red Hat, and Ubuntu

Linux is actually everywhere: It's in your phones, your thermostats, in your cars, refrigerators, and televisions. It also runs most of the Internet, all of the world’s top 500 supercomputers, and the world’s stock exchanges. But besides being the platform of choice to run desktops, servers, and embedded systems across the globe, Linux is one of the most reliable, secure and worry-free operating systems available.

WHY Command Line

Can do everything with command line and that too faster.