If you're learning DevOps, Cloud, or Backend Development, Linux is a skill you simply can't avoid.

Most production servers run Linux. Docker containers run on Linux. Kubernetes is built around Linux. Even many cloud services are powered by Linux.

As part of my DevOps learning journey, I started with the Linux fundamentals. In this article, I'll share the concepts and commands every beginner should know.

What is Linux?

Linux is an open-source operating system kernel that acts as the bridge between software and hardware.

It manages resources like:

  • CPU
  • Memory
  • Storage
  • Devices
  • Running processes

Whenever you execute a command, Linux communicates with the hardware on your behalf.

Popular Linux Distributions

Linux comes in many distributions (often called distros), each designed for different use cases.

Debian-Based

Examples:

  • Ubuntu
  • Debian

Package Manager:

apt

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These distributions are popular among developers because they're easy to use and have excellent community support.

Red Hat-Based

Examples:

  • Red Hat Enterprise Linux (RHEL)
  • CentOS
  • Fedora
  • Amazon Linux

Package Managers:

yum

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or

dnf

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These are commonly used in enterprise environments.

Alpine Linux

Package Manager

apk

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Alpine is extremely lightweight and is widely used for Docker containers.

Understanding the Linux File System

Unlike Windows, Linux has a single directory tree that starts from the root directory.

/
├── bin/
├── boot/
├── dev/
├── etc/
├── home/
├── lib/
├── media/
├── mnt/
├── opt/
├── proc/
├── root/
├── sbin/
├── tmp/
├── usr/
└── var/

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Here's what each directory is used for.

Directory Purpose
/bin Essential command binaries like ls, cp, and cat
/boot Bootloader and Linux kernel
/dev Device files (USB, disks, terminals, etc.)
/etc System configuration files
/home Home directories for normal users
/lib Shared libraries used by applications
/media Automatically mounted removable media
/mnt Temporary mount point
/opt Optional third-party software
/proc Information about running processes
/root Home directory of the root user
/sbin System administration commands
/tmp Temporary files
/usr User applications and documentation
/var Logs, caches, databases, and changing data

Navigating the File System

Show Current Directory 

pwd

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Displays your current working directory.

List Files 

ls

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Lists files and folders.

Detailed list:

ls -l

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Include hidden files:

ls -la

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Change Directory

Go to another directory:

cd /var/log

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Go back one level:

cd ..

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Go to your home directory:

cd ~

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Return to the previous directory:

cd -

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Understanding Paths

Absolute Path

Always starts from the root directory.

Example:

/home/mohiuddin/projects/app.py

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No matter where you currently are, this path always points to the same file.

Relative Path

Relative paths depend on your current location.

Example:

projects/app.py

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If you're already inside:

/home/mohiuddin

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then both paths point to the same file.

Useful Shortcuts

Shortcut Meaning
. Current directory
.. Parent directory
~ Home directory
cd - Previous directory

Basic File Operations

Create a Directory 

mkdir project

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Create nested directories:

mkdir -p project/src/components

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Copy Files 

cp file.txt backup.txt

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Copy directories recursively:

cp -r folder1 folder2

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Move or Rename Files

Rename:

mv old.txt new.txt

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Move:

mv notes.txt /tmp/

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Remove Files

Delete a file:

rm file.txt

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Delete a directory:

rm -r folder

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Force delete:

rm -rf folder

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⚠️ Warning: rm -rf permanently deletes files without asking for confirmation. Always double-check the path before running it.

Create an Empty File 

touch notes.txt

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Display File Contents 

cat notes.txt

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Example output:

Today I learned Linux basics.

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Quick Command Reference

Command Description
pwd Show current directory
ls List files
ls -la Show all files including hidden
cd Change directory
mkdir Create directory
cp Copy files
mv Move or rename files
rm Remove files
touch Create empty file
cat Display file contents

Final Thoughts

Linux is one of the most valuable skills for software developers, especially if you're interested in DevOps, Cloud Computing, Docker, Kubernetes, or Backend Development.

These commands may seem simple, but you'll use them every day when working with servers and containers.

I'm currently documenting my DevOps learning journey, and I'll continue sharing beginner-friendly guides on Git, Docker, Kubernetes, Jenkins, Terraform, AWS, and more.

If you have any tips for Linux beginners, feel free to share them in the comments.

Happy Learning! 🐧