# Linux Linux is a free and open-source Unix-like operating system kernel created by [[Linus Torvalds]] in 1991. What began as a personal project while he was a student at the University of Helsinki has become the foundation of modern computing infrastructure, powering the majority of web servers, cloud platforms, supercomputers, and Android devices. The term "Linux" technically refers to the kernel, while complete operating systems built around it are called "Linux distributions" (distros). These combine the kernel with GNU tools, package managers, and desktop environments to create usable systems. ## Key Characteristics - **Open source**: Licensed under GPL, freely available and modifiable - **Multiuser & multitasking**: Designed for concurrent users and processes - **Portable**: Runs on everything from embedded devices to supercomputers - **Security**: Strong permission model and rapid security patches - **Package management**: Distributions provide software repositories ## Major Distributions | Family | Distributions | Package Manager | |--------|--------------|-----------------| | Debian-based | [[Debian]], [[Ubuntu]], Linux Mint | apt/dpkg | | Red Hat-based | Fedora, RHEL, CentOS | dnf/rpm | | Arch-based | [[Arch Linux]], Manjaro, [[Omarchy]] | pacman | | Independent | [[Gentoo]], Slackware, NixOS | portage/various | ## Usage - **Servers**: ~96% of top web servers run Linux - **Cloud**: AWS, Google Cloud, Azure primarily run Linux workloads - **Supercomputers**: 100% of TOP500 supercomputers run Linux - **Mobile**: Android is built on the Linux kernel - **Embedded**: Routers, IoT devices, smart TVs - **Desktop**: Growing adoption with distros like Ubuntu and Fedora ## References - https://kernel.org - https://en.wikipedia.org/wiki/Linux ## Related - [[Linus Torvalds]] - [[Git]] - [[Arch Linux]] - [[Omarchy]] - [[Debian]] - [[Ubuntu]] - [[Gentoo]] - [[Alpine Linux]] - [[LazyGit]]