Linux

Linux, short for Linux Kernel, is a free and open-source Unix-like operating system kernel created by Linus Torvalds in 1991. It serves as the core component of many operating systems known as Linux distributions, which bundle the kernel with utilities, libraries, and tools to form a complete environment. Popular distributions include Ubuntu, Debian, Fedora, and Arch Linux. Linux can be downloaded through distribution providers such as Ubuntu Downloads, Debian Downloads, and Fedora Downloads.

Linux exists to provide a flexible, secure, and high-performance foundation for computing across servers, desktops, embedded devices, and supercomputers. Its design philosophy emphasizes modularity, stability, and openness, allowing developers to customize and extend functionality while maintaining strong performance and reliability.

Linux: File Structure

Linux uses a hierarchical file structure rooted at /. Common directories include /home, /etc, /var, and /usr.

/ ├── home ├── etc ├── var └── usr

This structure organizes system files, user data, configuration files, and applications in a consistent and predictable manner.

Linux: Basic Commands

Command-line utilities are central to interacting with Linux. Common commands include ls, cd, cp, mv, and rm.

# List files ls -la
Change directory

cd /home/user

Copy a file

cp file.txt backup.txt

Remove a file

rm file.txt

These commands allow users to navigate the filesystem, manage files, and perform administrative tasks efficiently.

Linux: Permissions and Ownership

Linux uses a permission model based on read (r), write (w), and execute (x) for user, group, and others.

# Change permissions chmod 755 script.sh
Change ownership

chown user:group file.txt

Permissions ensure controlled access to files and directories, contributing to system security and multi-user operation.

Linux: Process Management

Processes represent running programs. Tools like ps, top, and kill are used to manage them.

# View running processes ps aux
Monitor system processes

top

Kill a process

kill -9 1234

These tools help monitor performance, debug issues, and control execution of applications.

Linux is used across servers, cloud infrastructure, embedded devices, and personal computers. It integrates with technologies such as Bash, Python, and Docker to build scalable, efficient, and customizable computing environments.