An operating system acts as the bridge between user and hardware. Linux is a powerful open-source family built around the Linux Kernel, created by Linus Torvalds in 1991. When combined with tools and interfaces, the kernel creates a full system known as a Linux distribution or 'distro'. Popular examples include Ubuntu, which offers beginners an accessible entry point.

Linux dominates servers and cloud environments, while Windows and macOS lead consumer desktops. Android is actually based on the Linux Kernel, powering billions of mobile devices. Its popularity in infrastructure stems from being secure, stable, and highly customizable. Unlike closed-source competitors, Linux grants full control, making it the foundation for much of the internet's backend.

Major providers like Amazon Web Services, Google Cloud, and Microsoft Azure rely heavily on Linux to power their virtual machines. The Linux operating system market reached USD 21.97 billion in 2024, with projections to hit USD 99.69 billion by 2032. By the end of 2024, every top 500 supercomputer ran on Linux, cementing its technical dominance.