Phase 1: Foundation
Before you can understand how the kernel works or how containers are isolated, you need to feel comfortable in Linux day-to-day. Phase 1 covers the concepts that every Linux user and engineer relies on constantly — from how the filesystem is organized to how the shell processes your commands.
What You'll Learn
1. What is Linux?
Kernel vs OS, distributions, why Linux runs the world's servers.
Beginner2. Directory Structure
Every major directory explained: /, /etc, /proc, /sys, /var and more.
Beginner3. Terminal & Shell
stdin/stdout/stderr, pipes, redirection, PATH, environment variables.
Beginner4. File Permissions
rwx bits, octal notation, chmod, chown, umask, special bits.
Beginner5. Users, Groups & sudo
/etc/passwd, UID/GID, root, sudoers, principle of least privilege.
Beginner6. Package Managers
APT, DNF, Pacman — how software installs, repositories, dependency resolution.
Beginner7. File Systems
ext4, btrfs, xfs — what they do and how Linux mounts them.
Beginner8. Hard vs Soft Links
What actually happens on disk when you create a link.
Beginner9. Inodes
How the kernel tracks files internally — the real identity of every file.
BeginnerWhy Start Here?
Trying to learn cgroups or eBPF without knowing what an inode is like trying to understand TCP without knowing what a socket is. These fundamentals show up everywhere — in error messages, in documentation, in job interviews, and in real debugging sessions. Invest the time here and everything later clicks faster.