Day 2: Introduction to Linux and Basic Commands

Table of Contents

1. What is Linux?
2. History of Linux
3. Basic Linux Commands

What is Linux
Linux is a free and open-source operating system modeled on UNIX. It’s the software that sits between your computer’s hardware and the applications you run, managing resources and enabling communication between them. Unlike proprietary systems like Windows or macOS, Linux is built collaboratively by developers around the world and is known for its stability, security, and flexibility

Key Features of Linux

1. Open source: Anyone can view, modify, and distribute the code.
2. Stable: Rarely crashes and handles long uptimes.
3. Secure: Fewer viruses and robust user permission control.
4. Flexible: Can be customized for desktops, servers, embedded devices.
5. Multi-user and multitasking: Supports multiple users and concurrent tasks efficiently.

History of Linux

How Linux Took Over the Tech World—In Simple Terms

• Early 1990s: A curious student named Linus Torvalds builds a small program (kernel) as a personal project. He shares it online, inviting others to join the ride.

• 1991: The first version of “Linux” is born. It's like the central engine (or heart) of a computer—but it needs other pieces to become fully usable.

• Mid-1990s to 2000s: Developers across the globe start adding the missing tools and features. Different versions, called "distributions" like Ubuntu, Fedora, and Red Hat—start popping up.

• 2000s: Linux becomes a go-to for powering servers. It later grows into mobile tech, forming the foundation for Android.

• Today: Linux is everywhere—in phones, laptops, smart devices, cloud infrastructure, supercomputers, and even spacecraft. Thanks to open collaboration, it keeps evolving.

Basic Linux Commands

Command	Description
ls	List files and directories
pwd	Show current directory path
cd [dir]	Change directory
mkdir [dir]	Create new directory
rmdir [dir]	Remove empty directory
rm [file]	Delete file
rm -r [dir]	Delete directory and contents
cp [src] [dest]	Copy file or directory
mv [src] [dest]	Move/rename file or directory
touch [file]	Create empty file
cat [file]	View file content
nano [file]	Edit file using nano editor
sudo apt install [pkg]	Install package
sudo apt remove [pkg]	Remove package

✅ Why Use Linux?

• Free to use and distribute
• Highly customizable
• Supported by a large global community
• Used in cloud computing, DevOps, cybersecurity, AI, and more