Linux

Linux refers to a family of open-source Unix-like operating systems built around the Linux kernel. The term typically describes a complete OS that combines the Linux kernel with system libraries, utilities, and applications, most notably the GNU userland, though distributions may include software from other sources. The Linux kernel was created by Linus Torvalds in 1991 and released under the GNU General Public License. It is developed by a global community of contributors and is provided free of charge.

A Linux distribution, or distro, packages the kernel with a cohesive set of software to form an operating system. Examples include Debian, Ubuntu, Fedora, Red Hat Enterprise Linux, Arch, and SUSE. Distros differ in package management, default software, documentation, and target use cases. Package managers such as apt, dnf, pacman, and zypper facilitate software installation and updates, while various initialization systems coordinate startup processes.

Linux architecture features a monolithic kernel that supports loadable modules, multitasking, multiuser operation, strong portability, and wide hardware driver support. The kernel runs on a broad range of architectures, from embedded devices and personal computers to servers and mainframes. Most modern distros pair the kernel with large collections of userland tools and graphical environments, enabling diverse workloads and environments.

Init systems and filesystems vary by distribution, with systemd being widely adopted for service management in many popular distros, alongside alternatives such as OpenRC and SysVinit. Common filesystems include ext4, btrfs, and xfs, among others, chosen for performance, reliability, and features.

Linux plays a major role in servers, cloud infrastructure, supercomputers, and embedded systems, and forms the basis of Android’s kernel. Its development model emphasizes openness, collaboration, and interoperability across hardware and software ecosystems.