operating system
also: OS, kernel, Linux kernel
An operating system (OS) is the core software that manages a computer's hardware resources and provides essential services for applications and users. Linux is a free, open-source operating system kernel that powers everything from servers to smartphones.
An operating system acts as an intermediary between users/applications and physical hardware. It manages critical resources including the CPU, memory, storage devices, and peripherals, ensuring fair allocation and preventing conflicts.
Linux specifically refers to the kernel—the core component that handles low-level tasks like process scheduling, memory management, and device drivers. When combined with GNU utilities and other software, it forms a complete Linux distribution (like Ubuntu, Fedora, or Debian) that users can install and run.
For example, when you run a command like ls to list files, the shell passes your request to the Linux kernel, which accesses the filesystem and returns results. The OS abstracts away hardware complexity, so you don't need to know the exact details of your storage device to read files.