Lesson 1 / 29

Linux Introduction

What Linux is, its kernel, and the distros built on top of it.

What is Linux?

Linux is a free, open-source kernel originally created by Linus Torvalds in 1991. Combined with system tools and a package manager, it forms a complete operating system that powers servers, phones (Android), and supercomputers.

Distros at a glance

A distribution (distro) bundles the Linux kernel with software and a package manager. Ubuntu/Debian are beginner-friendly and use apt. Fedora/RHEL/CentOS favor dnf/yum. Arch is minimal and rolling-release.

Everything is a file

A core Linux philosophy: devices, processes, even network sockets are represented as files under /dev, /proc, and /sys. This uniformity is why so many tools compose well together.