Lesson 1: What is Linux & Why DevOps Cares

Linux is a kernel — the core program that talks to hardware (CPU, RAM, disks, network). Distributions (Ubuntu, Debian, Fedora, Arch, Rocky) bundle the kernel + userland tools + package manager.

Why DevOps Runs on Linux

• Automation-first: Everything is a file, everything scriptable
• Container native: Docker/containerd run Linux namespaces/cgroups
• Server dominance: 96%+ of top 1M web servers run Linux
• Tool ecosystem: Ansible, Terraform, Kubernetes, CI/CD all assume Linux

Key Mental Model

Hardware → Kernel → Shell (bash/zsh) → You

You type commands → shell asks kernel → kernel talks to hardware.

What's Next

Lesson 2: Getting a VPS & Your First SSH Connection.