CENT OS

🧩 1. Basic Information

Field —>Description
OS Name —>CentOS (Community ENTerprise OS)
Developer —>Initially the CentOS community; later Red Hat sponsored
First Released —>May 2004
Latest Stable Version —>CentOS Stream 9 (2021–2025)
License Type —>Open source (GPL, various free licenses)
Supported Platforms —>x86-64 (primary), also ARM64
Still Active? —>⚠️ EOL for classic CentOS Linux; CentOS Stream continues

⚙️ 2. Kernel & Architecture

Kernel Type: Monolithic Linux kernel (from Red Hat Enterprise Linux - RHEL)

Based On: Upstream source code of Red Hat Enterprise Linux

Architecture Support: Primarily x86-64, also ARM64 in newer streams

Boot System: GRUB2, supports BIOS & UEFI

Package Management: rpm (Red Hat Package Manager) with yum & dnf

🌟 3. Key Features

Binary-compatible with RHEL (before stream shift)

Robust server platform — widely used for hosting & enterprise workloads

SELinux for mandatory access control (enhanced security)

Scalable from small VPS to large clusters

Virtualization ready (KVM, Xen, Docker, Podman)

Stable long-term support (historically ~10 years per release before shift to Stream)

📈 4. Version History & Important Milestones ✅

Version —>Year —>Milestone / Impact

CentOS 3–5 —>2004–07 —>Early adoption, clone of RHEL 3–5
CentOS 6 —>2011 —>Very popular in hosting, stable for years
CentOS 7 —>2014 —>systemd adoption, long lifespan (till 2024)
CentOS 8 —>2019 —>Major update, GNOME 3, DNF default
CentOS Stream launched —>2019 —>Rolling preview between Fedora & RHEL
CentOS Linux EOL —>2021 —>Moved fully to CentOS Stream; traditional CentOS 8 ended early
CentOS Stream 9 —>2021± –>Ongoing rolling-release style for next RHEL preview

🎯 5. Target Audience & Use Cases

Web & application servers: Most popular for cPanel, Apache, NGINX, PHP stacks

Enterprise workloads: Virtualization hosts, database servers

Developers: Who want to build apps for eventual RHEL deployment

Education labs: Teaching Linux system admin on a stable base

Anyone needing a free RHEL-compatible system

✅ 6. Pros & Cons

Pros —>Cons
Historically 100% binary compatible with RHEL —>CentOS Linux classic EOL caused confusion
Free, open source, no license fees —>CentOS Stream less stable than old CentOS Linux
Strong ecosystem for enterprise tools —>Some vendors only certify on full RHEL
SELinux & great security hardening options —>Transition to Stream means faster updates, not always “slow stable”

🎨 7. UI Demo & Visuals

Default GNOME desktop (CentOS 7 & 8)

Classic “Activities” overview in GNOME 3

Terminal demos: yum install, dnf update, firewall-cmd

Web server running on Apache with CentOS logo

Optionally cockpit admin GUI (via browser)

📦 8. Ecosystem & App Support

Uses rpm packages, managed via yum or dnf

Access to EPEL (Extra Packages for Enterprise Linux) repo for thousands more packages

Compatible with Docker, Podman, Kubernetes setups

Wide array of web & database stacks (LAMP, LEMP, MariaDB, PostgreSQL)

🔐 9. Security & Updates

SELinux for advanced security enforcement

Regular updates via yum / dnf

Firewalld default firewall management

SSH by default, easy to harden for server security

CentOS Stream gets fixes & features ahead of official RHEL releases

🌍 10. Community, License & Development

License: Fully open source (GPL, LGPL, MIT — depending on components)

Very large global user base, forums, IRC, dedicated StackExchange sites

Now developed under Red Hat sponsorship, more transparent under Stream

Developers use it to test future RHEL-compatible deployments

Massive documentation from Red Hat & community wikis