Linux Fundamentals Basics

Here’s a simple, easy-to-read version of PART 1: BASICS for your Linux notes or study guide:

---

✅ PART 1: BASICS

---

1. 🕰️ History of Linux Operating System

• Linux was created in 1991 by Linus Torvalds, a student from Finland.
• It started as a free and open-source alternative to UNIX.
• Over time, it became a powerful OS used in servers, supercomputers, Android phones, and even smart devices.

---

2. 🌐 The Open Source Project and OSI

• Open Source means the source code is open to everyone to view, use, and modify.
• The Open Source Initiative (OSI) checks if software licenses follow open-source rules.
• Open source promotes collaboration, sharing, and innovation.

---

3. 📜 Open Source Licenses and Standards

Licenses explain how you can use or share open-source software.

• GPL (General Public License)

  • You can use, change, and share it.
  • But if you share modified code, you must share the source code too.

• LGPL (Lesser GPL)

  • Similar to GPL but allows linking with non-GPL software.

• CDDL (Common Development and Distribution License)

  • More flexible, but not always compatible with GPL.

These licenses protect user freedom while allowing collaboration.

---

4. 🐧 Overview of Major Linux Distributions (Distros)

Linux comes in many flavors, called distributions (distros). Each one is a bit different.

Distribution	Best For	Notes
Ubuntu	Beginners	User-friendly, based on Debian
Debian	Stability	Very stable, used in servers
Fedora	Developers	New features, backed by Red Hat
Arch	Advanced users	Lightweight, fully customizable
AlmaLinux / Rocky	Servers	Based on Red Hat, used in enterprises
Kali Linux	Security experts	Tools for hacking and security testing

---

5. 🏗️ Overview of the Different Linux OS Architecture

Linux has a layered architecture:

1. Hardware – Physical parts (CPU, RAM, disk)
2. Kernel – The core that talks to the hardware
3. Shell – Interface for users to type commands (e.g., Bash)
4. Applications – Programs like web browsers, text editors, etc.

This design makes Linux modular, secure, and stable.

---