Linux is a monolithic, open-source, Unix-like operating system kernel. The term is also used to refer to the entire family of operating systems based on the Linux kernel. It is the dominant operating system for servers, supercomputers, and embedded devices.
Linux runs the internet. Its stability, security model, and open source nature made it the foundation of the cloud, containerization (cgroups/namespaces), and modern devops tooling. Understanding Linux internals is a prerequisite for advanced infrastructure engineering.
Linux is the only operating system that matters for our server infrastructure. We respect the philosophy: "Everything is a file." We prioritize deep Linux knowledge (systemd, eBPF, TCP stack tuning) over surface-level GUI interactions.