What is Linux? History & Distributions

Linux is more than just an operating system—it's the backbone of modern computing infrastructure. From web servers to Android phones, supercomputers to embedded devices, Linux powers the digital world. Let's explore its fascinating history and diverse ecosystem of distributions.

What Exactly is Linux?

At its core, Linux is a free and open-source Unix-like operating system kernel first released by Linus Torvalds in 1991. But when people say "Linux," they're usually referring to complete operating systems built around this kernel.

Key Insight: Linux itself is just the kernel. The complete operating system you use is typically a "Linux distribution" (distro) that bundles the kernel with software packages, tools, and a desktop environment.

The Birth of Linux: A Timeline

1991

The Beginning

Linus Torvalds, a Finnish computer science student, announces his "hobby" project—a free operating system kernel. The first version (0.01) was released in September.

1992

GNU/Linux Partnership

Linux kernel is combined with GNU software, creating the first complete free operating system. Adopts the GPL license, ensuring it remains free and open-source.

1993

First Distributions

Debian and Slackware emerge as the first major Linux distributions, making Linux more accessible to non-technical users.

1994

Linux 1.0

First production-ready Linux kernel release (version 1.0.0) with networking support and improved stability.

Major Linux Distribution Families

Linux distributions can be grouped into several major families, each with its own package management and philosophy.

🐧

Debian Family

Package Manager: APT
Examples: Ubuntu, Linux Mint
Focus: Stability, ease of use

🔴

Red Hat Family

Package Manager: YUM/DNF
Examples: RHEL, CentOS, Fedora
Focus: Enterprise, stability

🎯

Arch Family

Package Manager: Pacman
Examples: Arch Linux, Manjaro
Focus: Simplicity, customization

🔄

SUSE Family

Package Manager: Zypper
Examples: openSUSE, SLES
Focus: Enterprise, YaST tools

Popular Linux Distributions for DevOps

Ubuntu Server

Ubuntu Server is the most popular choice for cloud deployments and web servers. Its extensive documentation and community support make it ideal for DevOps workflows.

Common Ubuntu Commands:
sudo apt update && sudo apt upgrade
sudo systemctl status nginx
sudo ufw allow ssh

CentOS/RHEL

Red Hat Enterprise Linux and its free counterpart CentOS are staples in enterprise environments, known for their stability and long-term support.

Common RHEL/CentOS Commands:
sudo yum update (or sudo dnf update)
sudo firewall-cmd --add-service=http
sudo semanage port -a -t http_port_t -p tcp 8080

Amazon Linux

Specifically optimized for AWS environments, Amazon Linux includes tools and configurations tailored for cloud deployment.

Important Note: When choosing a distribution for production, consider factors like support lifecycle, security updates, package availability, and community support. What works for development might not be suitable for production.

Linux in Modern Infrastructure

Linux's dominance in several key areas demonstrates its importance:

Web Servers: Over 90% of the top 1 million web servers run Linux
Cloud Infrastructure: Major cloud providers (AWS, Google Cloud, Azure) rely heavily on Linux
Containers: Docker and Kubernetes are built on Linux container technologies
Supercomputers: All top 500 supercomputers run Linux
Mobile: Android is based on the Linux kernel

Getting Started with Linux

# Check your current Linux distribution
cat /etc/os-release

# Check kernel version
uname -r

# Check available disk space
df -h

# Check memory usage
free -h

# Check running processes
ps aux

Key Takeaways

Linux has evolved from a student's hobby project to the foundation of modern computing infrastructure. Its open-source nature, stability, and flexibility make it the ideal choice for everything from embedded devices to enterprise servers. Understanding Linux distributions and their characteristics is the first step toward mastering system administration and DevOps practices.

Next Step: Explore the Linux filesystem hierarchy and basic command-line operations to build your foundational skills.