Major Linux distributions - Learn Tech From Zero

1.1 Linux Evolution and Popular Operating Systems (Weight: 2)

📘Linux Essentials (LPI 010-160)

A Linux distribution (or “distro”) is a complete package that includes the Linux kernel (the core of the operating system) plus other software, such as a desktop environment, utilities, and package managers, which make it ready to use. Different distributions are tailored for different purposes: desktop use, server use, security testing, cloud, or embedded systems.

Here are the main Linux distributions you need to know:

1. Debian

Origin: Debian is one of the oldest Linux distributions.
Package management: Uses .deb packages and the APT (Advanced Package Tool) system.
Key features:
- Stable and reliable.
- Has a huge number of precompiled packages (software).
Common uses in IT:
- Servers (web, email, database).
- Base for other distros like Ubuntu.
- Cloud environments and virtual machines.

Example: Many cloud providers offer Debian images for easy deployment of web servers.

2. Ubuntu

Origin: Based on Debian.
Package management: .deb packages and APT.
Key features:
- Beginner-friendly.
- Regular release cycles (every 6 months) and long-term support (LTS) versions.
- Large community support.
Common uses in IT:
- Desktop workstations for developers.
- Servers for web hosting and cloud applications.
- Popular in DevOps environments for automation and CI/CD pipelines.

Example: Companies often use Ubuntu LTS servers to run applications like Apache, Nginx, or MySQL.

3. Red Hat Enterprise Linux (RHEL)

Origin: Commercial Linux from Red Hat.
Package management: .rpm packages using YUM or DNF.
Key features:
- Commercial support and subscription-based updates.
- Very stable and secure, suitable for enterprises.
Common uses in IT:
- Enterprise servers (finance, telecom, healthcare).
- Production environments where stability and security are critical.

Example: Banks often run RHEL for their internal databases and ERP systems because of its reliability and long-term support.

4. CentOS / Rocky Linux / AlmaLinux

Origin: Community versions based on RHEL.
Package management: .rpm with YUM/DNF.
Key features:
- Free to use.
- Binary-compatible with RHEL, meaning software written for RHEL works on these.
Common uses in IT:
- Web servers and application servers.
- Test and development servers before deploying to RHEL.

Example: A development team might use CentOS to test applications before moving them to RHEL in production.

5. Fedora

Origin: Community-supported by Red Hat.
Package management: .rpm with DNF.
Key features:
- Cutting-edge software.
- Short release cycle (about every 6 months).
- Often used to test new technologies before they appear in RHEL.
Common uses in IT:
- Developers testing latest software features.
- Learning and experimenting with new Linux technologies.

Example: A software developer uses Fedora to try out the latest versions of Python or container tools like Docker and Podman.

6. SUSE Linux / openSUSE

Origin: German company SUSE.
Package management: .rpm with Zypper.
Key features:
- Stable enterprise version: SUSE Linux Enterprise Server (SLES).
- Community version: openSUSE (Leap for stability, Tumbleweed for rolling releases).
Common uses in IT:
- Enterprise servers, especially in Europe.
- Virtualization and SAP environments.

Example: Businesses running SAP HANA databases often use SLES for its enterprise support and reliability.

7. Arch Linux

Origin: Independent distribution from the community.
Package management: Pacman.
Key features:
- Rolling release: always up-to-date.
- Lightweight and minimal; you install only what you need.
- Popular among experienced users.
Common uses in IT:
- Personal servers and desktops where users want full control.
- Learning about Linux internals.

Example: A Linux enthusiast might use Arch Linux on a home lab server to configure everything from scratch, learning deeply how Linux works.

8. Other Notable Distributions

Kali Linux: Based on Debian, used for security testing and ethical hacking.
Linux Mint: Based on Ubuntu, designed for desktop users with easy-to-use interface.
Raspberry Pi OS (formerly Raspbian): Based on Debian, optimized for Raspberry Pi devices in IoT or educational projects.

Key Points to Remember for the Exam

Linux distributions are different in package management, release cycles, stability, and support.
Debian-based: Debian, Ubuntu, Linux Mint, Raspberry Pi OS → use .deb and APT.
RHEL-based: RHEL, CentOS, Rocky Linux, AlmaLinux, Fedora, SUSE → use .rpm and YUM/DNF/Zypper.
Use cases matter:
- Enterprise servers → RHEL, SLES.
- Cloud servers → Ubuntu, Debian.
- Security testing → Kali.
- Learning and personal projects → Arch, Fedora, openSUSE.
Community vs. commercial: Some distributions are free with community support (Ubuntu, CentOS, Fedora), while others are paid with enterprise support (RHEL, SLES).