Linux distribution

A Linux distribution (often shortened to distro) is an operating system made from a collection of software, including the Linux kernel and often a package of GNU system software and libraries. For the end user, a Linux distribution is essentially the complete operating system they install and interact with, which makes the underlying kernel and other free software usable.

Distributions are developed by various projects and companies to serve different purposes and user needs. They bundle the core components of Linux (like the kernel, shell, init system, command-line tools) with additional software such as a package manager, software repositories, system libraries, utilities, and often a Desktop environment or a set of server applications.

The existence of many different distributions is due to the flexible and open-source nature of Linux. Anyone can take the source code for the kernel and other free software, customize it, and bundle it into their own distribution tailored for specific hardware, use cases, or user preferences.

Components of a Distribution

While the exact contents vary, a typical Linux distribution includes:

The Linux Kernel: The core of the OS that manages hardware and processes.
System Software: Essential utilities and daemons, often from the GNU Project (like the GNU core utilities), providing basic command-line functionality, file manipulation, and system management.
Init System: The first process started during booting, responsible for starting other system services (commonly systemd, but others like SysVinit or OpenRC exist).
System Libraries: Collections of code that applications use to perform common tasks (like the GNU C Library - glibc).
Package Management System: Tools (like APT, DNF, Pacman, apk) that automate the installation, updating, configuration, and removal of software packages from online repositories.
Software Repositories: Organized collections of pre-compiled software packages that can be easily installed via the package manager.
File System Hierarchy: A standard layout for directories and files on the system.
Shell: A command-line interface (CLI) that allows users to interact with the OS) by typing commands (Bash is the most common).
User Interface: For desktop distributions, this includes a windowing system (like X.Org or Wayland) and a desktop environment (GUI like GNOME, KDE Plasma, XFCE). Server distributions often omit the GUI and rely on the CLI.
Applications: Various user-facing or server applications (web browsers, office suites, web servers, database servers, development tools, etc.).

Types of Distributions

Linux distributions are often categorized based on their primary focus or development model:

**Desktop Distributions:** Designed for everyday use on personal computers, often featuring user-friendly GUIs and a wide range of pre-installed applications (e.g., Ubuntu, Linux Mint, Fedora).
**Server Distributions:** Optimized for stability, security, and running server applications. They often have minimal installations, focus on command-line tools, and provide LTS releases (e.g., Debian Stable, Ubuntu Server, RHEL, CentOS Stream).
**Embedded Distributions:** Small, specialized distributions for use in embedded systems and devices with limited resources (e.g., Buildroot, OpenWrt, Alpine Linux).
**Security Distributions:** Focused on computer security tasks, often including pre-installed tools for penetration testing, digital forensics, or secure environments (e.g., Kali Linux, Tails, Qubes OS).
**Lightweight Distributions:** Designed for older hardware or systems with limited resources, often using lighter desktop environments or window managers.
**Rolling Release vs. Release-based:** This refers to the update model. Rolling release distributions continuously receive the latest software updates, while release-based distributions have distinct versions released periodically, with updates focused on bug and security fixes until the next major release.

Most Used Distribution Tree

Many Linux distributions are derived from or based on other distributions, forming "families" or "trees." Below is a simplified representation focusing on some of the most widely used distributions and their relationships. Note that this is not exhaustive, and popularity can vary by use case (desktop vs. server) and region.

**Debian Family:** Known for its commitment to free software, stability, and APT package manager.

   * Debian (The base distribution)
       * Ubuntu (Popular desktop and server distribution, easier to use, has its own release cycle)
           * Linux Mint (Very popular desktop distribution, focuses on user-friendliness)
           * Pop!_OS (Desktop distribution by System76, includes optimizations)
           * Raspberry Pi OS (Formerly Raspbian, official distribution for Raspberry Pi hardware)
       * Kali Linux (Security-focused distribution)
       * Tails (Security-focused, live system emphasizing anonymity)

**Red Hat Family:** Originally based on Red Hat Linux, now centered around RHEL for enterprise servers and Fedora as the upstream. Uses the DNF (and historically RPM) package manager.

   * Fedora (Community distribution, upstream for RHEL, uses newer software)
   * RHEL (Commercial enterprise server distribution, focuses on stability and support)
       * CentOS Stream (Community distribution, rolling release, upstream for RHEL)
       * AlmaLinux (Community-supported RHEL clone)
       * Rocky Linux (Community-supported RHEL clone)

**SUSE Family:** Another major historical branch, known for the YaST configuration tool. Uses the Zypper (and RPM) package manager.

   * openSUSE (Community distribution, has rolling release ('Tumbleweed') and release-based ('Leap') options)
   * SUSE Linux Enterprise Server (Commercial enterprise server distribution)

**Other Notable Independent Distributions:**

   * Slackware (One of the oldest still-maintained distributions, known for simplicity and limited automation)
   * Gentoo (Known for its source-based package management (Portage), allowing high customization)
   * Arch Linux (Known for its simplicity, minimalism, and rolling release model; uses Pacman package manager)
       * Manjaro (Popular desktop distribution based on Arch Linux, easier to install and use)

References

Template:Cite web - Website tracking releases and popularity (based on page hits) of Linux distributions.
Template:Cite web - Official Debian website.
Template:Cite web - Official Ubuntu website.
Template:Cite web - Official Fedora website.
Template:Cite web - Official RHEL page.
Template:Cite web - Official Arch Linux website.
Template:Cite book - Discusses various Linux distributions from an administration perspective.

Linux distribution

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