1. What is Linux?
Linux is an open-source Unix-like operating system kernel originally created by Linus Torvalds in 1991. It forms the core of various Linux distributions (distros) like Ubuntu, CentOS, Debian, and Red Hat. The kernel manages hardware resources, processes, memory, and provides a foundation for applications to run on. Linux is known for its stability, security, and flexibility, making it the dominant operating system for servers, cloud infrastructure, embedded systems, and increasingly for desktop computing. Unlike proprietary operating systems, Linux's open-source nature allows anyone to view, modify, and distribute the source code. Linux follows the Unix philosophy of small, modular tools that work together. It's used by major tech companies like Google, Amazon, Facebook, and Netflix for their infrastructure. Understanding Linux is fundamental for DevOps, system administration, cloud computing, and backend development careers.