Introduction to Linux

What is Linux?

Linux is an open-source operating system kernel that powers the majority of servers, cloud infrastructure, and DevOps tooling worldwide. Understanding Linux is the foundation of any DevOps career.

Why Linux for DevOps?

Server dominance — Over 90% of cloud servers run Linux
Open source — Free to use, modify, and distribute
Automation friendly — Powerful command-line interface
Container foundation — Docker and Kubernetes run on Linux
Tool ecosystem — Most DevOps tools are Linux-native

Linux Distributions

A Linux distribution (distro) packages the Linux kernel with additional software, package managers, and configurations.

Popular Distributions

Distribution	Use Case	Package Manager
Ubuntu	General purpose, beginners	apt
CentOS/Rocky	Enterprise servers	yum/dnf
Debian	Stability-focused servers	apt
Alpine	Containers (minimal)	apk
Amazon Linux	AWS workloads	yum

Setting Up Your Environment

For this course, we recommend using Ubuntu 22.04 LTS. Here are your options:

Option 1: Virtual Machine

# Using VirtualBox or VMware
# Download Ubuntu ISO from ubuntu.com
# Create a new VM with 2GB RAM, 20GB disk

Option 2: WSL (Windows Users)

# Open PowerShell as Administrator
wsl --install -d Ubuntu-22.04

Option 3: Cloud Instance

# Create a free-tier EC2 instance on AWS
# Or use a free VPS from Oracle Cloud

Your First Commands

Once you have a Linux terminal open, try these commands:

# Check your Linux version
cat /etc/os-release
 
# See who you're logged in as
whoami
 
# Print the current date
date
 
# See your current directory
pwd

Summary

In this lesson, you learned:

Linux is the foundation of modern DevOps infrastructure
There are many distributions, each suited for different purposes
You can run Linux via VM, WSL, or cloud instances
Basic commands help you interact with the system

Next Steps

In the next lesson, we'll dive into the Linux file system and learn to navigate directories like a pro.

Learning Objectives