Introduction

What is Linux?

Linux is a Unix-like open source operating system. At the core of the operating system is the Linux kernel. It acts as the intermediary between the applications which run in the operating system and the underlying hardware.

Linux Distributions

A Linux distribution is the Linux kernel and a collection of software that, together, creates an operating system. Even though the Linux kernel is at the heart of every distribution, the software that is installed by default can vary greatly as each distribution its own goals and areas of focus. However, what you will learn in this book is applicable to any distribution as the concepts are fundamental to the Linux operating system as a whole.

Some distros (distributions) are maintained by a community of volunteers, while others are backed by companies that charge fees for subscriptions and support. Some distros are designed to run on laptops and desktops, while others are designed to run on servers. The following are just a few of the most popular Linux distributions available today:

• Linux Mint
• Ubuntu
• Debian
• Fedora
• openSUSE
• Arch Linux
• CentOS
• Red Hat Enterprise Linux