Linux Chapter 1

Linux is Everywhere!

●Linux is everywhere, Linux jobs are everywhere, there is a shortage of Linux talent,
and, Linux skills are in demand in just about every industry and job category on the
planet.

Linux is a Kernel

●Linux means the kernel of the system, which is the central controller of everything
that happens on the computer.

●Linux is a combination of software called GNU/Linux, which defines the operating
system.

○GNU is the free software that provides open source equivalents of many common UNIX
commands.

○The Linux part of this combination is the Linux kernel, which is the core of the operating
system.

●The story of Linux begins with UNIX, an operating system developed at AT&T Bell Labs
in the 1970s.

●UNIX is written in the C language.

Linux is a Kernel

●Linux started in 1991 as a hobby project by Linus Torvalds, a Finnish born computer
scientist studying at the University of Helsinki.

●The GNU Project was developed Linux by Richard Stallman in 1983.

●Linux programmers were able to incorporate the GNU tools to provide a complete
operating system.

Linux is Open Source

●Historically, most software has been issued under a closed-source license.

●This means that you get the right to use the executable program or machine code,
but cannot see the source code.

●The development of Linux closely parallels the rise of open source software.

●The open source philosophy is that you have a right to obtain the software source
code and to modify it for your own use.

Linux Has Distributions

●A distribution refers to the Linux kernel, tools, and suite of applications that come
bundled together.

●Take Linux and the GNU tools, add some user-facing applications like a web browser
and an email client, and you have a full Linux system.

●There are distributions suited to every imaginable purpose.

●There are distributions that focus on running servers, desktops, or even
industry-specific tools like electronics design or statistical computing.

Linux Embraces the CLI

●There are two basic types of interfaces available that allow you to interact with the
operating system.

●The typical computer user today is most familiar with a graphical user interface
(GUI).

○In a GUI, applications present themselves in windows that can be resized and moved around.

○There are menus and tools to help users navigate.

●The second type of interface is the command line interface (CLI), a text-based
interface to the computer.

○The CLI relies primarily on keyboard input.