Linux Distribution System

What is a Linux Distribution?

The Linux kernel is just the core — it manages hardware, memory, and processes. A distribution (distro) bundles the kernel together with:

• A package manager

• A init system (usually systemd)

• Core utilities (GNU tools, bash, …)

• Optional: desktop environment, installer, default apps

There are 600+ active distros. Most trace back to one of three major families.

The Three Major Families

Debian

The oldest community-driven family. Known for stability and the .deb package format.

Debian
├── Ubuntu               # Most popular desktop/server distro
│   ├── Linux Mint       # Beginner-friendly, Windows-like UI
│   ├── Pop!_OS          # Developer & gaming focus (System76)
│   ├── elementary OS    # macOS-inspired design
│   └── Kubuntu / Xubuntu / Lubuntu   # Ubuntu + different DEs
├── Kali Linux           # Penetration testing & security
├── Raspberry Pi OS      # Optimised for Raspberry Pi hardware
└── MX Linux             # Lightweight, stable, highly rated

Package manager: apt / dpkg Package format: .deb

Red Hat

Enterprise-focused family. Favours stability over cutting-edge packages.

Red Hat
├── RHEL (Red Hat Enterprise Linux)   # Paid, enterprise support
│   ├── CentOS Stream    # Upstream preview of RHEL
│   ├── AlmaLinux        # Free RHEL binary-compatible rebuild
│   └── Rocky Linux      # Free RHEL binary-compatible rebuild
└── Fedora               # Community distro, leads RHEL features
    └── (feeds into RHEL every ~2 years)

Package manager: dnf / rpm Package format: .rpm

Arch

Rolling-release family. Always the latest packages; users build their system from scratch.

Arch
├── Arch Linux           # Minimal, DIY, bleeding-edge
├── Manjaro              # Arch with a user-friendly installer
├── EndeavourOS          # Arch with guided setup
└── Garuda Linux         # Gaming & performance-tuned

Package manager: pacman Package format: .pkg.tar.zst Extra: AUR (Arch User Repository) — community-built packages

Other Notable Distros

Release Models

Fixed release

Versions ship on a schedule (e.g. every 6 months or 2 years). Packages are frozen at release and only receive security patches.

• More stable and predictable

• Software can lag behind upstream

• Examples: Ubuntu LTS, Debian stable, RHEL

Rolling release

No versions — packages update continuously as upstream releases them.

• Always up to date

• Slightly higher risk of breakage

• Examples: Arch, openSUSE Tumbleweed, Manjaro

LTS (Long-Term Support)

A fixed release with an extended support window (typically 5–10 years). Ideal for servers.

• Ubuntu LTS: supported for 5 years (10 with Extended Security Maintenance)

• RHEL: 10-year lifecycle

Package Managers at a Glance

Universal package formats

These work across distros:

Init Systems

The init system is PID 1 — the first process the kernel starts. It brings up everything else.

# systemd — common commands
systemctl status nginx
systemctl start nginx
systemctl enable nginx    # start on boot
journalctl -u nginx -f    # follow logs for a unit

Kernel Versions

All distros run the Linux kernel but ship different versions:

uname -r          # print running kernel version
# Example outputs:
# 6.8.0-51-generic      ← Ubuntu (stable, patched)
# 6.14.2-arch1-1        ← Arch   (latest upstream)
# 5.14.0-503.el9.x86_64 ← RHEL 9 (enterprise LTS)

• Mainline — Linus Torvalds' tree, latest features

• Stable — backported fixes from mainline

• LTS kernel — long-term maintained stable branch (e.g. 6.6 LTS)

• Vendor kernel — distro patches applied on top (most common in practice)

Choosing a Distro

Quick Reference

# Identify your distro
cat /etc/os-release
lsb_release -a        # on Debian-based systems

# Check kernel version
uname -r

# Check architecture
uname -m              # x86_64, aarch64, …